// Numbas version: exam_results_page_options {"name": "Integration by Substitution", "feedback": {"allowrevealanswer": true, "showtotalmark": true, "advicethreshold": 0, "intro": "", "feedbackmessages": [], "showanswerstate": true, "showactualmark": true}, "timing": {"allowPause": true, "timeout": {"action": "none", "message": ""}, "timedwarning": {"action": "none", "message": ""}}, "allQuestions": true, "shuffleQuestions": false, "percentPass": 0, "duration": 0, "pickQuestions": 0, "navigation": {"onleave": {"action": "none", "message": ""}, "reverse": true, "allowregen": true, "showresultspage": "oncompletion", "preventleave": true, "browse": true, "showfrontpage": true}, "metadata": {"description": "

Integration by Substitution

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rebelmaths

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rebel

", "licence": "Creative Commons Attribution 4.0 International"}, "type": "exam", "questions": [], "showQuestionGroupNames": false, "question_groups": [{"name": "", "pickingStrategy": "all-ordered", "pickQuestions": 0, "questions": [{"name": "Definite Integration 2", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Bill Foster", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/6/"}], "functions": {}, "tags": ["Calculus", "calculus", "definite integration", "integration", "integration by parts", "integration by parts twice"], "advice": "\n

 

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b)
\\[\\begin{eqnarray*}I&=&\\int_0^{\\var{b2}}\\simplify[std]{1/(x+{m2})}\\;dx\\\\ &=&\\left[\\ln(x+\\var{m2})\\right]_0^{\\var{b2}}\\\\ &=& \\ln(\\var{b2+m2})-\\ln(\\var{m2})\\\\ &=&\\ln\\left(\\frac{\\var{b2+m2}}{\\var{m2}}\\right)\\\\ &=&\\var{ans2}\\mbox{ to 2 decimal places} \\end{eqnarray*} \\]

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\n ", "rulesets": {"std": ["all", "fractionNumbers", "!collectNumbers", "!noLeadingMinus"]}, "parts": [{"prompt": "\n

\\[I=\\int_0^{\\var{b1}}\\simplify[std]{e^({a}x)}\\;dx\\]

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$I=\\;\\;$[[0]]

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Input your answer to 3 decimal places.

\n ", "gaps": [{"minvalue": "ans1-tol", "type": "numberentry", "maxvalue": "ans1+tol", "marks": 1.0, "showPrecisionHint": false}], "type": "gapfill", "marks": 0.0}, {"prompt": "\n

\\[I=\\int_0^{\\var{b2}}\\simplify[std]{1/({b}x+{m2})}\\;dx\\]

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$I=\\;\\;$[[0]]

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Input your answer to 3 decimal places.

\n ", "gaps": [{"minvalue": "ans2-tol", "type": "numberentry", "maxvalue": "ans2+tol", "marks": 1.0, "showPrecisionHint": false}], "type": "gapfill", "marks": 0.0}, {"prompt": "\n

\\[I=\\int_0^{\\pi/2}\\simplify[std]{({w} * Sin({m3} * x) + {1 -w} * Cos({m3} * x))}\\;dx\\]

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$I=\\;\\;$[[0]]

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Input your answer to 3 decimal places.

\n ", "gaps": [{"minvalue": "ans3-tol", "type": "numberentry", "maxvalue": "ans3+tol", "marks": 1.0, "showPrecisionHint": false}], "type": "gapfill", "marks": 0.0}], "statement": "

Evaluate the following definite integrals.

", "variable_groups": [], "progress": "ready", "type": "question", "variables": {"a": {"definition": "random(-2..2#0.5 except 0)", "name": "a"}, "m2": {"definition": "random(1..9)", "name": "m2"}, "b": {"definition": "random(2..5)", "name": "b"}, "w": {"definition": "random(0,1)", "name": "w"}, "s2": {"definition": "random(1,-1)", "name": "s2"}, "ans2": {"definition": "precround(1/b*(ln(1+b*b2/m2)),3)", "name": "ans2"}, "ans3": {"definition": "precround(tans3,3)", "name": "ans3"}, "b2": {"definition": "random(1..20)", "name": "b2"}, "b1": {"definition": "random(-1..2#0.5 except 0)", "name": "b1"}, "tol": {"definition": 0.001, "name": "tol"}, "t": {"definition": "random(1,-1)", "name": "t"}, "m3": {"definition": "random(2..9)", "name": "m3"}, "ans1": {"definition": "precround(tans1,3)", "name": "ans1"}, "c1": {"definition": "t*random(1..9)", "name": "c1"}, "tans1": {"definition": "(1/a)*(e^(a*b1)-1)", "name": "tans1"}, "tol1": {"definition": 0.0001, "name": "tol1"}, "tans3": {"definition": "1/m3*((1-w)*sin(m3*pi/2)-w*(cos(m3*pi/2)-1))", "name": "tans3"}, "d1": {"definition": "random(-9..9)", "name": "d1"}}, "metadata": {"notes": "\n \t\t \t\t

3/07/1012:

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Added tags.

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Checked calculations.

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Left tolerances in, as easy to make minor errors in calculations.

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Improved display in Advice.

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Some superscripts e.g. the form a^\\var{b} in latex have to be written as a^{\\var{b}} as not displayed properly (if b has a second digit it slips down). Corrected.

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20/07/2012:

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Set new tolerace variables, tol=0.01, tol1=0.0001.

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Can have expressions in Advice of the form $1\\times E$ where E is an expression. This can be remedied by rewriting - but later as not crucial.

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Added description.

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25/07/2012:

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Added tags.

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A lot of work in this question - Perhaps it would be more managable broken down into two separate questions?

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Question appears to be working correctly.

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\n \t\t \n \t\t", "description": "

Evaluate $\\int_0^{\\,m}e^{ax}\\;dx$, $\\int_0^{p}\\frac{1}{bx+d}\\;dx,\\;\\int_0^{\\pi/2} \\sin(qx) \\;dx$. 

", "licence": "Creative Commons Attribution 4.0 International"}, "showQuestionGroupNames": false, "question_groups": [{"name": "", "pickingStrategy": "all-ordered", "pickQuestions": 0, "questions": []}]}, {"name": "Integration by substitution", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "TEAME UCC", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/351/"}], "functions": {}, "metadata": {"licence": "Creative Commons Attribution 4.0 International", "description": "

Integration by substitution. Hint given on susbtitution

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rebelmaths

"}, "statement": "

Complete the following indefinite integrals using integration by substition and the letter C for any unknown constants.

", "ungrouped_variables": ["c", "a", "f", "d", "b"], "variablesTest": {"condition": "", "maxRuns": 100}, "variables": {"c": {"name": "c", "definition": "random(5..12)", "description": "", "group": "Ungrouped variables", "templateType": "anything"}, "f": {"name": "f", "definition": "random(3..5 except d)", "description": "", "group": "Ungrouped variables", "templateType": "anything"}, "b": {"name": "b", "definition": "random(1..10)", "description": "", "group": "Ungrouped variables", "templateType": "anything"}, "a": {"name": "a", "definition": "random(2..6)", "description": "", "group": "Ungrouped variables", "templateType": "anything"}, "d": {"name": "d", "definition": "random(2..9)", "description": "", "group": "Ungrouped variables", "templateType": "anything"}}, "tags": ["rebelmaths"], "preamble": {"js": "", "css": ""}, "rulesets": {}, "variable_groups": [], "advice": "

Use the substitution given

", "parts": [{"checkvariablenames": false, "variableReplacementStrategy": "originalfirst", "showpreview": true, "prompt": "

$\\int \\cos(\\var{a}x) \\mathrm{dx}$ using the substitution $u = \\var{a}x$.

", "variableReplacements": [], "checkingaccuracy": 0.001, "answer": "sin({a}x)/{a} + C", "expectedvariablenames": [], "showCorrectAnswer": true, "checkingtype": "absdiff", "vsetrange": [0, 1], "marks": 1, "showFeedbackIcon": true, "type": "jme", "scripts": {}, "vsetrangepoints": 5}, {"checkvariablenames": false, "variableReplacementStrategy": "originalfirst", "showpreview": true, "prompt": "

$\\int x(\\var{b}+x^2)^\\var{c}\\mathrm{dx}$ using the substitution $u = \\var{b} + x^2$.

", "variableReplacements": [], "checkingaccuracy": 0.001, "answer": "({b}+x^2)^({c}+1)/(2({c}+1))+C", "expectedvariablenames": [], "showCorrectAnswer": true, "checkingtype": "absdiff", "vsetrange": [0, 1], "marks": 1, "showFeedbackIcon": true, "type": "jme", "scripts": {}, "vsetrangepoints": 5}, {"checkvariablenames": false, "variableReplacementStrategy": "originalfirst", "showpreview": true, "prompt": "

$\\int\\frac{\\mathrm{dt}}{(1-\\var{d}t)^\\var{f}}$ using the substitution $u = 1-\\var{d}t$

", "variableReplacements": [], "checkingaccuracy": 0.001, "answer": "1/({d}({f}-1)(1-{d}t)^({f}-1))+C", "expectedvariablenames": [], "showCorrectAnswer": true, "checkingtype": "absdiff", "vsetrange": [0, 1], "marks": 1, "showFeedbackIcon": true, "type": "jme", "scripts": {}, "vsetrangepoints": 5}], "type": "question"}, {"name": "Leicester: Integration1", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Bill Foster", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/6/"}], "functions": {"chcp": {"definition": "if(gcd(a,b)=1,b,chcp(a,random(2..9)))", "type": "number", "language": "jme", "parameters": [["a", "number"], ["b", "number"]]}}, "tags": [], "advice": "", "rulesets": {"std": ["all", "fractionNumbers", "!collectNumbers"]}, "parts": [{"notallowed": {"message": "

Input all numbers as integers or fractions and not as decimals.

", "showstrings": false, "strings": ["."], "partialcredit": 0.0}, "prompt": "\n

$\\displaystyle f(x)=\\simplify[std]{{a}*x^({b}/{c})}$

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Input $\\displaystyle \\int f(x)\\;dx$ here.

\n

 

\n ", "checkingaccuracy": 0.001, "vsetrange": [0.0, 1.0], "vsetrangepoints": 5.0, "checkingtype": "absdiff", "answersimplification": "std", "marks": 1.0, "answer": "{a*c}/{b+c}*x^({b+c}/{c})+C", "type": "jme"}, {"prompt": "\n

$f(x)=\\simplify[std]{{t[0]}*sin({b}x+{c})+{t[1]}*cos({b}x+{c})+{t[2]}*exp({b}x+{c})}$

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Input $\\displaystyle \\int f(x)\\;dx$ here.

\n ", "checkingaccuracy": 0.001, "vsetrange": [0.0, 1.0], "vsetrangepoints": 5.0, "checkingtype": "absdiff", "answersimplification": "std", "marks": 1.0, "answer": "(1/{b})*({-t[0]}*cos({b}x+{c})+{t[1]}*sin({b}x+{c})+{t[2]}*exp({b}x+{c}))+C", "type": "jme"}, {"notallowed": {"message": "

Input all numbers as integers or fractions and not as decimals.

", "showstrings": false, "strings": ["."], "partialcredit": 0.0}, "prompt": "\n

$f(x)=\\simplify[std]{{a}exp({b}/{c}*x)}$

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Input $\\displaystyle \\int f(x)\\;dx$ here.

\n ", "checkingaccuracy": 0.001, "vsetrange": [0.0, 1.0], "vsetrangepoints": 5.0, "checkingtype": "absdiff", "answersimplification": "std", "marks": 1.0, "answer": "{a*c}/{b}*exp({b}/{c}*x)+C", "type": "jme"}, {"notallowed": {"message": "

Input all numbers as integers or fractions and not as decimals.

", "showstrings": false, "strings": ["."], "partialcredit": 0.0}, "prompt": "\n

$\\displaystyle f(x)=\\simplify[std]{{a1}/({b1}x+{c1})}$

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Input $\\displaystyle \\int f(x)\\;dx$ here.

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\n ", "checkingaccuracy": 0.001, "vsetrange": [0.0, 1.0], "vsetrangepoints": 5.0, "checkingtype": "absdiff", "answersimplification": "std", "marks": 1.0, "answer": "{a1}/{b1}ln(abs({b1}x+{c1}))+C", "type": "jme"}], "statement": "\n

Integrate the following functions $f(x)$.

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Input all numbers as integers or fractions and not as decimals.

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In all examples do not forget to include the constant of integration $C$.

\n ", "variable_groups": [], "progress": "ready", "type": "question", "variables": {"a": {"definition": "random(-9..9 except [-1,0,1])", "name": "a"}, "c": {"definition": "random(2..9)", "name": "c"}, "b": {"definition": "chcp(c,2)", "name": "b"}, "a1": {"definition": "random(-9..9 except[0,a])", "name": "a1"}, "u": {"definition": "random(1,2,3)", "name": "u"}, "t": {"definition": "switch(u=1,[1,0,0],u=2,[0,1,0],[0,0,1])", "name": "t"}, "c1": {"definition": "chcp(b1,2)", "name": "c1"}, "b1": {"definition": "random(2..9)", "name": "b1"}}, "metadata": {"notes": "", "description": "

Integrating simple functions.

", "licence": "Creative Commons Attribution 4.0 International"}, "showQuestionGroupNames": false, "question_groups": [{"name": "", "pickingStrategy": "all-ordered", "pickQuestions": 0, "questions": []}]}, {"name": "Integration by substitution 2", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "TEAME UCC", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/351/"}], "variablesTest": {"condition": "", "maxRuns": 100}, "rulesets": {}, "preamble": {"css": "", "js": ""}, "metadata": {"description": "

Integration by susbtitution, no hint given

", "licence": "Creative Commons Attribution 4.0 International"}, "functions": {}, "tags": [], "variables": {"b": {"description": "", "definition": "random(1..8 except a)", "name": "b", "templateType": "anything", "group": "Ungrouped variables"}, "a": {"description": "", "definition": "random(2..6)", "name": "a", "templateType": "anything", "group": "Ungrouped variables"}, "c": {"description": "", "definition": "random(1..9)", "name": "c", "templateType": "anything", "group": "Ungrouped variables"}}, "parts": [{"prompt": "

$\\int e^x\\sqrt{1+e^x}\\mathrm{dx}$

", "checkingaccuracy": 0.001, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "showpreview": true, "type": "jme", "showCorrectAnswer": true, "answer": "2(1+e^x)^(3/2)/3+C", "scripts": {}, "vsetrange": [0, 1], "vsetrangepoints": 5, "marks": 1, "checkingtype": "absdiff", "checkvariablenames": false, "expectedvariablenames": [], "showFeedbackIcon": true}, {"prompt": "

$\\int\\frac{\\mathrm{dx}}{\\var{a}x+\\var{b}}$.

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Answer in terms of the natural log, represented by ln( ).

", "checkingaccuracy": 0.001, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "showpreview": true, "type": "jme", "showCorrectAnswer": true, "answer": "1/{a}ln({a}x+{b})+C", "scripts": {}, "vsetrange": [0, 1], "vsetrangepoints": 5, "marks": 1, "checkingtype": "absdiff", "checkvariablenames": false, "expectedvariablenames": [], "showFeedbackIcon": true}, {"prompt": "

$\\int \\frac{x \\mathrm{dx}}{\\var{c}+x^2}$.

\n

Answer in terms of the natural log, represented by ln( ).

", "checkingaccuracy": 0.001, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "showpreview": true, "type": "jme", "showCorrectAnswer": true, "answer": "ln({c}+x^2)/2+C", "scripts": {}, "vsetrange": [0, 1], "vsetrangepoints": 5, "marks": 1, "checkingtype": "absdiff", "checkvariablenames": false, "expectedvariablenames": [], "showFeedbackIcon": true}], "variable_groups": [], "ungrouped_variables": ["c", "b", "a"], "advice": "

integration by Susbtitution

", "statement": "

Evaluate the following indefinite integrals using integration by substitution. Use the letter C to represent any unknown constants.

", "type": "question"}, {"name": "Julie's copy of Hannah's copy of Indefinite integral by substitution", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Julie Crowley", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/113/"}], "functions": {}, "tags": ["Calculus", "Steps", "calculus", "indefinite integration", "integrals", "integration", "integration by substitution", "steps", "substitution"], "advice": "\n\t

This exercise is best solved by using substitution.
Note that if we let $u=\\simplify[std]{{a} * (x ^ 2) + {b}}$ then $du=\\simplify[std]{({2*a} * x)*dx }$
Hence we can replace $xdx$ by $\\frac{1}{\\var{2*a}}du$.

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Hence the integral becomes:

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\\[\\begin{eqnarray*} I&=&\\simplify[std]{Int((1/{2*a})u^{m},u)}\\\\ &=&\\simplify[std]{(1/{2*a})u^{m+1}/{m+1}+C}\\\\ &=& \\simplify[std]{({a} * (x ^ 2) + {b})^{m+1}/{2*a*(m+1)}+C} \\end{eqnarray*}\\]

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A Useful Result
This example can be generalised.
Suppose \\[I = \\int\\; f'(x)g(f(x))\\;dx\\]
The using the substitution $u=f(x)$ we find that $du=f'(x)\\;dx$ and so using the same method as above:
\\[I = \\int g(u)\\;du \\]
And if we can find this simpler integral in terms of $u$ we can replace $u$ by $f(x)$ and get the result in terms of $x$.

\n\t", "rulesets": {"std": ["all", "!collectNumbers", "fractionNumbers", "!noLeadingMinus"]}, "parts": [{"prompt": "\n\t\t\t

\\[I=\\simplify[std]{Int( x*({a} * x ^ 2 + {b})^{m},x)}\\]

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$I=\\;$[[0]]

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Input numbers in your answer as integers or fractions and not as decimals.

\n\t\t\t", "gaps": [{"notallowed": {"message": "

Input all numbers as integers or fractions and not as decimals.

", "showstrings": false, "strings": ["."], "partialcredit": 0.0}, "expectedvariablenames": [], "checkingaccuracy": 0.001, "vsetrange": [0.0, 1.0], "vsetrangepoints": 5.0, "checkingtype": "absdiff", "answersimplification": "std", "marks": 3.0, "answer": "({a} * (x ^ 2) + {b})^{m+1}/{2*a*(m+1)}+C", "checkvariablenames": false, "type": "jme"}], "type": "gapfill", "marks": 0.0}], "statement": "\n\t

Find the following integral.

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Input the constant of integration as $C$.

\n\t \n\t \n\t", "variable_groups": [], "progress": "ready", "type": "question", "variables": {"a": {"definition": "random(1..5)", "name": "a"}, "s1": {"definition": "random(1,-1)", "name": "s1"}, "b": {"definition": "s1*random(1..9)", "name": "b"}, "m": {"definition": "random(4..9)", "name": "m"}}, "metadata": {"notes": "\n\t\t \t\t \t\t

2/08/2012:

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Added tags.

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Added description.

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Checked calculation. OK.

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Added information about Show steps in prompt content area. 

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Added decimal point as forbidden string and included message in prompt about not entering decimals.

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Got rid of a redundant ruleset.

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\n\t\t \t\t \n\t\t \n\t\t", "description": "

Find $\\displaystyle \\int x(a x ^ 2 + b)^{m}\\;dx$

", "licence": "Creative Commons Attribution 4.0 International"}, "showQuestionGroupNames": false, "question_groups": [{"name": "", "pickingStrategy": "all-ordered", "pickQuestions": 0, "questions": []}]}, {"name": "Julie's copy of Indefinite integral", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Julie Crowley", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/113/"}], "metadata": {"notes": "\n\t\t \t\t

2/08/2012:

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Added tags.

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Added description.

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Corrected mistake in formula for integrating $\\sin(ax)$ in Steps and Advice.

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Checked calculation. OK.

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Added decimal point to forbidden strings along with message to user re input of numbers.

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Message about Show steps included. Also another message about including the constant of integration.

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Changed checking range from 0 to 1 to 1 to 2 as we can have negative powers of $x$.

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Improved display of Steps by aligning integral signs.

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Find $\\displaystyle \\int ae ^ {bx}+ c\\sin(dx) + px ^ {q}\\;dx$.

", "licence": "Creative Commons Attribution 4.0 International"}, "question_groups": [{"questions": [], "pickingStrategy": "all-ordered", "pickQuestions": 0, "name": ""}], "parts": [{"type": "gapfill", "steps": [{"marks": 0.0, "type": "information", "prompt": "

Note that \\[\\begin{eqnarray*} &\\int& \\;x^n\\;dx&=&\\frac{x^{n+1}}{n+1}+C,\\;\\;n \\neq -1\\\\ &\\int& \\;\\sin(ax)\\;dx &=& -\\frac{1}{a}\\cos(ax)+C\\\\ &\\int& \\;e^{ax}\\;dx &=& \\frac{1}{a}e^{ax}+C\\\\ \\end{eqnarray*}\\]

"}], "stepspenalty": 0.0, "marks": 0.0, "gaps": [{"checkingtype": "absdiff", "vsetrange": [1.0, 2.0], "type": "jme", "checkingaccuracy": 0.001, "answer": "({b}/{a}) * (e ^({a}*x)) + (({(-b1)}/{a1}) * Cos({a1}*x)) + ({a2}/{c3+1}) * (x ^ {(c3 + 1)})+C", "showpreview": true, "notallowed": {"strings": ["."], "partialcredit": 0.0, "showstrings": false, "message": "

Input all numbers as integers or fractions and not decimals.

"}, "answersimplification": "std", "marks": 2.0, "vsetrangepoints": 5.0, "checkvariablenames": false, "expectedvariablenames": []}], "prompt": "\n

$\\simplify[std]{f(x) = {b} * e ^ ({a}*x) + {b1} * Sin({a1}*x) + {a2} * x ^ {c3}}$

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$\\displaystyle \\int\\;f(x)\\,dx=\\;$[[0]]

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Input all numbers as integers or fractions and not decimals. Remember to include the constant of integration $C$.

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Click on Show steps to get more information. You will not lose any marks by doing so.

\n \n"}], "type": "question", "progress": "ready", "variables": {"s2": {"name": "s2", "definition": "random(1,-1)"}, "a": {"name": "a", "definition": "s1*random(2..5)"}, "s5": {"name": "s5", "definition": "random(1,-1)"}, "s1": {"name": "s1", "definition": "random(1,-1)"}, "c3": {"name": "c3", "definition": "s5*random(2..8)"}, "b1": {"name": "b1", "definition": "s3*random(2..9)"}, "b": {"name": "b", "definition": "s2*random(2..9)"}, "a1": {"name": "a1", "definition": "random(2..5)"}, "a2": {"name": "a2", "definition": "s4*random(3..9)"}, "s4": {"name": "s4", "definition": "random(1,-1)"}, "s3": {"name": "s3", "definition": "random(1,-1)"}}, "tags": ["Calculus", "Steps", "calculus", "constant of integration", "exponential function", "indefinite integration", "integrals", "integrating powers", "integration", "integration of exponential function", "integration of powers", "integration of trigonometric functions", "standard integrals", "steps", "trigonometric functions"], "advice": "\n

Note that \\[\\begin{eqnarray*} &\\int& \\;x^n\\;dx&=&\\frac{x^{n+1}}{n+1}+C,\\;\\;n \\neq -1\\\\ &\\int& \\;\\sin(ax)\\;dx &=& -\\frac{1}{a}\\cos(ax)+C\\\\ &\\int& \\;e^{ax}\\;dx &=& \\frac{1}{a}e^{ax}+C\\\\ \\end{eqnarray*}\\]

\n

Splitting the integral into three parts and using the above information we have:
\\[\\begin{eqnarray*}\\simplify[std]{Int({b} * e ^ ({a}*x) + {b1} * Sin({a1}*x) + {a2} * x ^ {c3},x)}&=&\\simplify[std]{Int({b} * e ^ ({a}*x),x)+Int({b1} * Sin({a1}*x),x)+Int({a2} * x ^ {c3},x) }\\\\ &=&\\simplify[std]{({b}/{a}) * (e ^({a}*x)) + (({(-b1)}/{a1}) * Cos({a1}*x)) + ({a2}/{c3+1}) * (x ^ {(c3 + 1)})+C} \\end{eqnarray*}\\]

\n \n", "rulesets": {"std": ["all", "!collectNumbers", "fractionNumbers"], "surdf": [{"pattern": "a/sqrt(b)", "result": "(sqrt(b)*a)/b"}]}, "variable_groups": [], "statement": "\n

Integrate the following function $f(x)$.

\n

 
Input the constant of integration as $C$.

\n \n", "showQuestionGroupNames": false, "functions": {}}, {"name": "Julie's copy of Indefinite integral", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Julie Crowley", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/113/"}], "functions": {}, "statement": "\n\t \n\t \n\t

Find the following indefinite integral.

\n\t \n\t \n\t \n\t

Input the constant of integration as $C$.

\n\t \n\t \n\t \n\t", "progress": "ready", "metadata": {"licence": "Creative Commons Attribution 4.0 International", "description": "

Find $\\displaystyle \\int \\frac{a}{(bx+c)^n}\\;dx$

", "notes": "\n\t\t \t\t

2/08/2012:

\n\t\t \t\t

Added tags.

\n\t\t \t\t

Added description.

\n\t\t \t\t

Added decimal point to forbidden strings along with message to user re input of numbers.

\n\t\t \t\t

Added a Step and message about Show steps included - losing 1 mark if used as it gives the formula for finding the integral. Increased marks to 3 for the question, so that can cope with losing a mark for using Show steps.

\n\t\t \t\t

Changed accuracy setting to relative difference of 0.00001 as we have negative powers.

\n\t\t \t\t

Checked calculation. OK.

\n\t\t \t\t

Added message in prompt  about including the constant of integration.

\n\t\t \t\t

Noted issue with steps-answer order and the messages/marks generated.

\n\t\t \t\t

Changed numerator to the range 2..5.

\n\t\t \t\t

Improved display in Advice.

\n\t\t \t\t

 

\n\t\t \n\t\t"}, "parts": [{"stepspenalty": 1.0, "gaps": [{"answer": "(-{b})/({a*(n-1)}*({a}*x+{d})^{n-1}) + C", "vsetrangepoints": 5.0, "checkingtype": "reldiff", "vsetrange": [0.0, 1.0], "marks": 3.0, "type": "jme", "notallowed": {"message": "

Input all numbers as integers or fractions and not decimals.

", "strings": ["."], "showstrings": false, "partialcredit": 0.0}, "answersimplification": "std", "checkingaccuracy": 0.0001}], "prompt": "\n\t\t\t

$\\displaystyle \\int \\simplify[std]{{b}/(({a}*x+{d})^{n})} dx= \\phantom{{}}$[[0]]

\n\t\t\t

Input all numbers as integers or fractions and not decimals. Remember to include the constant of integration $C$.

\n\t\t\t

Click on Show steps to get help. You will lose 1 mark by doing so.

\n\t\t\t \n\t\t\t", "marks": 0.0, "type": "gapfill", "steps": [{"marks": 0.0, "type": "information", "prompt": "

 \\[\\int (ax+b)^n \\;dx = \\frac{1}{a(n+1)}(ax+b)^{n+1}+C\\]

"}]}], "variables": {"d": {"name": "d", "definition": "random(1..9)"}, "b": {"name": "b", "definition": "random(2..5)"}, "a": {"name": "a", "definition": "random(2..9)"}, "n": {"name": "n", "definition": "random(3..5)"}}, "tags": ["Calculus", "Steps", "calculus", "constant of integration", "indefinite integration", "integrals", "integration", "integration by substitution", "standard integrals", "steps", "substitution"], "question_groups": [{"pickQuestions": 0, "pickingStrategy": "all-ordered", "name": "", "questions": []}], "type": "question", "variable_groups": [], "advice": "\n\t

Let $y = \\simplify[std]{{a}*x+{d}}$. Then,
\\[\\simplify[std]{{b}/(({a}*x+{d})^{n})} = \\simplify[std]{{b}/(y^{n})}.\\]

\n\t

Now,
\\[\\int \\simplify[std]{{b}/({a}*x+{d})^{n}} dx = \\int \\simplify[std]{{b}/(y^{n})} \\frac{dx}{dy} dy.\\]

\n\t

Rearrange $y = \\simplify[std]{{a}x+{d}}$ to get $\\displaystyle x = \\simplify[std]{(y-{b})/{a}}$, and hence $\\displaystyle\\frac{dx}{dy} = \\frac{1}{\\var{a}}$.

\n\t

$\\displaystyle \\int \\frac{1}{y^n} dx = -\\frac{1}{(n-1)y^{n-1}} + C$ is a standard integral, so we can now calculate the desired integral:

\n\t

\\[\\int \\simplify[std]{{b}/(y^{n})} \\frac{dx}{dy} dy = \\simplify[std]{{b}/({n-1}*y^{n-1})} \\cdot \\frac{1}{\\var{a}} + C = \\simplify[std]{(-{b})/({a*(n-1)}*({a}*x+{d})^{n-1}) + C}.\\]

\n\t \n\t", "rulesets": {"std": ["all", "!collectNumbers", "fractionNumbers", "!noLeadingMinus"], "surdf": [{"pattern": "a/sqrt(b)", "result": "(sqrt(b)*a)/b"}]}, "showQuestionGroupNames": false}, {"name": "Julie's copy of Indefinite integral by substitution", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Julie Crowley", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/113/"}], "rulesets": {"std": ["all", "!collectNumbers", "fractionNumbers", "!noLeadingMinus"]}, "variable_groups": [], "metadata": {"notes": "\n\t\t \t\t

2/08/2012:

\n\t\t \t\t

Added tags.

\n\t\t \t\t

Added description.

\n\t\t \t\t

Checked calculation. OK.

\n\t\t \t\t

Added information about Show steps in prompt content area. 

\n\t\t \t\t

Got rid of a redundant ruleset. !noLeadingMinus added to std ruleset.

\n\t\t \n\t\t", "licence": "Creative Commons Attribution 4.0 International", "description": "

Find $\\displaystyle \\int \\sin(x)(a+ b\\cos(x))^{m}\\;dx$

"}, "showQuestionGroupNames": false, "advice": "\n\t \n\t \n\t

This exercise is best solved by using substitution.
Note that if we let $u=\\simplify[std]{{a}+{b}cos(x)}$ then $du=\\simplify[std]{({-b}*sin(x))*dx }$
Hence we can replace $\\sin(x)\\;dx$ by $\\frac{1}{\\var{-b}}\\;du$.

\n\t \n\t \n\t \n\t

Hence the integral becomes:

\n\t \n\t \n\t \n\t

\\[\\begin{eqnarray*} I&=&\\simplify[std]{Int((1/{-b})u^{m},u)}\\\\\n\t \n\t &=&\\simplify[std]{(1/{-b})u^{m+1}/{m+1}+C}\\\\\n\t \n\t &=& \\simplify[std]{({a}+{b}*cos(x))^{m+1}/{-b*(m+1)}+C}\n\t \n\t \\end{eqnarray*}\\]

\n\t \n\t \n\t \n\t", "functions": {}, "progress": "ready", "tags": ["Calculus", "Steps", "calculus", "constant of integration", "integrals", "integrating trigonometric functions", "integration", "integration by substitution", "steps", "substitution"], "variables": {"b": {"definition": "s1*random(1..9)", "name": "b"}, "m": {"definition": "random(3..9)", "name": "m"}, "s1": {"definition": "random(1,-1)", "name": "s1"}, "a": {"definition": "random(1..9)", "name": "a"}}, "parts": [{"prompt": "\n\t\t\t

\\[I=\\simplify[std]{Int( sin(x)*({a} + {b}*cos(x))^{m},x)}\\]

\n\t\t\t

Input all numbers as integers or fractions.

\n\t\t\t

$I=\\;$[[0]]

\n\t\t\t

Input the constant of integration as $C$.

\n\t\t\t

Click on Show steps if you need help. You will lose 1 mark if you do so.

\n\t\t\t \n\t\t\t", "stepspenalty": 1.0, "marks": 0.0, "steps": [{"prompt": "

Try the substitution $u=\\simplify[std]{{a}+{b}cos(x)}$

", "marks": 0.0, "type": "information"}], "type": "gapfill", "gaps": [{"notallowed": {"strings": ["."], "partialcredit": 0.0, "message": "

Do not input numbers as decimals, only as integers without the decimal point, or fractions.

", "showstrings": false}, "answer": "({a}+{b}*cos(x))^{m+1}/{-b*(m+1)}+C", "vsetrange": [0.0, 1.0], "vsetrangepoints": 5.0, "marks": 3.0, "answersimplification": "std", "checkingtype": "absdiff", "checkingaccuracy": 0.001, "type": "jme"}]}], "question_groups": [{"pickQuestions": 0, "pickingStrategy": "all-ordered", "name": "", "questions": []}], "type": "question", "statement": "\n\t

Find the following integral.

\n\t

Input the constant of integration as $C$.

\n\t

Input all numbers as integers or fractions not as decimals.

\n\t \n\t"}, {"name": "Julie's copy of Indefinite integral by substitution", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Julie Crowley", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/113/"}], "rulesets": {"std": ["all", "!collectNumbers", "fractionNumbers", "!noLeadingMinus"]}, "variable_groups": [], "metadata": {"notes": "\n\t\t \t\t \t\t

2/08/2012:

\n\t\t \t\t \t\t

Added tags.

\n\t\t \t\t \t\t

Added description.

\n\t\t \t\t \t\t

Checked calculation. OK.

\n\t\t \t\t \t\t

Added information about Show steps in prompt content area. 

\n\t\t \t\t \t\t

Added decimal point as forbidden string and included message in prompt about not entering decimals.

\n\t\t \t\t \t\t

Got rid of a redundant ruleset. !noLeadingMinus added to std ruleset.

\n\t\t \t\t \t\t

Note that the choice of variables means that the argument of the log answer is always $\\gt 0$ so no need to use abs.

\n\t\t \t\t \t\t

 

\n\t\t \t\t \n\t\t \n\t\t", "licence": "Creative Commons Attribution 4.0 International", "description": "

Find $\\displaystyle \\int \\frac{2ax + b}{ax ^ 2 + bx + c}\\;dx$

"}, "showQuestionGroupNames": false, "advice": "\n\t

This exercise is best solved by using substitution.

\n\t

Note that the numerator $\\simplify[std]{{2 * a} * x + {b}}$ of \\[\\simplify[std]{({2 * a} * x + {b}) / ({a} * x ^ 2 + {b} * x + {c})}\\] is the derivative of the denominator $\\simplify[std]{{a} * x ^ 2 + {b} * x + {c}}$

\n\t

So if you use as your substitution $u=\\simplify[std]{{a} * (x ^ 2) + ({b} * x) + {c}}$ you then have $\\simplify[std]{ du = ({2 * a} * x + {b}) * dx}$

\n\t

Hence we can replace $\\simplify[std]{ ({2 * a} * x + {b}) * dx}$ by $du$

\n\t

Hence the integral becomes:

\n\t

\\[\\begin{eqnarray*} I&=&\\int\\;\\frac{du}{u}\\\\ &=&\\ln(|u|)+C\\\\ &=& \\simplify[std]{ln(abs({a} * (x ^ 2) + ({b} * x) + {c}))+C} \\end{eqnarray*}\\]

\n\t

A Useful Result
This example can be generalised.
Suppose \\[I = \\int\\; \\frac{f'(x)}{f(x)}\\;dx\\]
The using the substitution $u=f(x)$ we find that $du=f'(x)\\;dx$ and so using the same method as above:
\\[I = \\int \\frac{du}{u} = \\ln(|u|)+ C = \\ln(|f(x)|)+C\\]

\n\t", "functions": {}, "progress": "ready", "tags": ["Steps", "calculus", "indefinite integration", "integration", "integration by substitution", "substitution"], "variables": {"test": {"definition": "4*a*c-b^2", "name": "test"}, "f": {"definition": "-a*(1+b1)^2", "name": "f"}, "b": {"definition": "2*a+b1", "name": "b"}, "a": {"definition": "random(1..5)", "name": "a"}, "c": {"definition": "a*b1^2+c1", "name": "c"}, "c1": {"definition": "max(-10,f+1)+random(1..5)", "name": "c1"}, "b1": {"definition": "s1*random(1..5)", "name": "b1"}, "s1": {"definition": "random(1,-1)", "name": "s1"}}, "parts": [{"prompt": "\n\t\t\t

\\[I=\\simplify[std]{Int(({2 * a} * x + {b}) / ({a} * x ^ 2 + {b} * x + {c}),x)}\\]

\n\t\t\t

$I=\\;$[[0]]

\n\t\t\t

Input the constant of integration as $C$.

\n\t\t\t

Input all numbers as integers or fractions not as decimals.

\n\t\t\t

Click on Show steps if you need help. You will lose 1 mark if you do so.

\n\t\t\t \n\t\t\t \n\t\t\t", "stepspenalty": 1.0, "marks": 0.0, "steps": [{"prompt": "

Try the substitution $u=\\simplify[std]{{a} * (x ^ 2) + ({b} * x) + {c}}$

", "marks": 0.0, "type": "information"}], "type": "gapfill", "gaps": [{"type": "jme", "checkingaccuracy": 0.001, "showpreview": true, "answersimplification": "std", "answer": "ln(abs((({a} * (x ^ 2)) + ({b} * x) + {c})))+C", "notallowed": {"strings": ["."], "partialcredit": 0.0, "message": "

Do not input numbers as decimals, only as integers without the decimal point, or fractions

", "showstrings": false}, "vsetrange": [0.0, 1.0], "vsetrangepoints": 5.0, "marks": 3.0, "checkingtype": "absdiff", "checkvariablenames": false, "expectedvariablenames": []}]}], "question_groups": [{"pickQuestions": 0, "pickingStrategy": "all-ordered", "name": "", "questions": []}], "type": "question", "statement": "\n\t

Find the following integral.

\n\t

Input the constant of integration as $C$.

\n\t

Input all numbers as integers or fractions.

\n\t

 

\n\t \n\t \n\t"}, {"name": "Julie's copy of Indefinite integral by substitution", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Julie Crowley", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/113/"}], "parts": [{"prompt": "\n\t\t\t

\\[I=\\simplify[std]{Int( x*({a} * x ^ 2 + {b})^{m},x)}\\]

\n\t\t\t

$I=\\;$[[0]]

\n\t\t\t

Input numbers in your answer as integers or fractions and not as decimals.

\n\t\t\t

Click on Show steps to get further help. You will lose 1 mark if you do so.

\n\t\t\t \n\t\t\t", "marks": 0.0, "steps": [{"prompt": "

Try the substitution $u=\\simplify[std]{{a} * (x ^ 2) + {b}}$

", "type": "information", "marks": 0.0}], "stepspenalty": 1.0, "gaps": [{"checkingtype": "absdiff", "answersimplification": "std", "checkingaccuracy": 0.001, "notallowed": {"strings": ["."], "message": "

Input all numbers as integers or fractions and not as decimals.

", "partialcredit": 0.0, "showstrings": false}, "type": "jme", "vsetrange": [0.0, 1.0], "marks": 3.0, "vsetrangepoints": 5.0, "answer": "({a} * (x ^ 2) + {b})^{m+1}/{2*a*(m+1)}+C"}], "type": "gapfill"}], "progress": "ready", "question_groups": [{"pickQuestions": 0, "name": "", "questions": [], "pickingStrategy": "all-ordered"}], "metadata": {"description": "

Find $\\displaystyle \\int x(a x ^ 2 + b)^{m}\\;dx$

", "notes": "\n\t\t \t\t

2/08/2012:

\n\t\t \t\t

Added tags.

\n\t\t \t\t

Added description.

\n\t\t \t\t

Checked calculation. OK.

\n\t\t \t\t

Added information about Show steps in prompt content area. 

\n\t\t \t\t

Added decimal point as forbidden string and included message in prompt about not entering decimals.

\n\t\t \t\t

Got rid of a redundant ruleset.

\n\t\t \t\t

 

\n\t\t \t\t

 

\n\t\t \n\t\t", "licence": "Creative Commons Attribution 4.0 International"}, "showQuestionGroupNames": false, "variables": {"a": {"name": "a", "definition": "random(1..5)"}, "m": {"name": "m", "definition": "random(4..9)"}, "s1": {"name": "s1", "definition": "random(1,-1)"}, "b": {"name": "b", "definition": "s1*random(1..9)"}}, "tags": ["Calculus", "Steps", "calculus", "indefinite integration", "integrals", "integration", "integration by substitution", "steps", "substitution"], "statement": "\n\t

Find the following integral.

\n\t

Input the constant of integration as $C$.

\n\t \n\t", "advice": "\n\t \n\t \n\t

This exercise is best solved by using substitution.
Note that if we let $u=\\simplify[std]{{a} * (x ^ 2) + {b}}$ then $du=\\simplify[std]{({2*a} * x)*dx }$
Hence we can replace $xdx$ by $\\frac{1}{\\var{2*a}}du$.

\n\t \n\t \n\t \n\t

Hence the integral becomes:

\n\t \n\t \n\t \n\t

\\[\\begin{eqnarray*} I&=&\\simplify[std]{Int((1/{2*a})u^{m},u)}\\\\\n\t \n\t &=&\\simplify[std]{(1/{2*a})u^{m+1}/{m+1}+C}\\\\\n\t \n\t &=& \\simplify[std]{({a} * (x ^ 2) + {b})^{m+1}/{2*a*(m+1)}+C}\n\t \n\t \\end{eqnarray*}\\]

\n\t \n\t \n\t \n\t

A Useful Result
This example can be generalised.
Suppose \\[I = \\int\\; f'(x)g(f(x))\\;dx\\]
The using the substitution $u=f(x)$ we find that $du=f'(x)\\;dx$ and so using the same method as above:
\\[I = \\int g(u)\\;du \\]
And if we can find this simpler integral in terms of $u$ we can replace $u$ by $f(x)$ and get the result in terms of $x$.

\n\t \n\t \n\t \n\t", "rulesets": {"std": ["all", "!collectNumbers", "fractionNumbers", "!noLeadingMinus"]}, "type": "question", "variable_groups": [], "functions": {}}, {"name": "Julie's copy of Indefinite integral", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Julie Crowley", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/113/"}], "functions": {}, "tags": ["Calculus", "Steps", "calculus", "constant of integration", "indefinite integration", "integration", "integration by substitution", "steps", "substitution"], "advice": "\n\t

Let $y = \\simplify[std]{{a}*x+{d}}$.

\n\t

Then $\\displaystyle x=\\frac{1}{\\var{a}}\\simplify[std]{(y-{d})}$ and so we have the numerator $\\simplify[std]{{b}*x+{c}}$ becomes in terms of $y$:

\n\t

$\\displaystyle \\simplify[std]{{b}*x+{c} = {b}*1/{a}*(y-{d})+{c}= {m}y+{r}}$ and so

\n\t

\\[\\displaystyle \\simplify[std]{({b}*x+{c})/(({a}*x+{d})^{n})} = \\simplify[std]{({m}*y+{r})/(y^{n})={m}/y^{n-1}+{r}/y^{n}}\\]

\n\t

Now,
\\[\\int \\simplify[std]{({b}x+{c})/({a}*x+{d})^{n}} dx = \\int \\left(\\simplify[std]{{m}/y^{n-1}+{r}/y^{n}} \\right)\\frac{dx}{dy} dy \\]

\n\t

Since $\\displaystyle x = \\simplify[std]{(y-{d})/{a}}$ then $\\displaystyle \\frac{dx}{dy} = \\frac{1}{\\var{a}}$.

\n\t

We can now calculate the desired integral:

\n\t

\\[ \\begin{eqnarray*} \\int \\left(\\simplify[std]{{m}/y^{n-1}+{r}/y^{n}}\\right) \\frac{dx}{dy} dy &=&\\frac{1}{\\var{a}}\\left(\\int \\simplify[std]{{m}/y^{n-1}}\\;dy+\\int \\simplify[std]{{r}/y^{n}}\\;dy \\right)\\\\ &=&\\frac{1}{\\var{a}}\\left(\\simplify[std]{{-m}/({n-2}*y^{n-2})+ {-r}/({n-1}*y^{n-1})}\\right) + C \\\\ &=& \\simplify[std]{(-{m})/({a*(n-2)}*({a}*x+{d})^{n-2})+(-{r})/({a*(n-1)}*({a}*x+{d})^{n-1}) + C}\\\\ &=&\\simplify[std]{1/({a}x+{d})^{n-1}*(({-m}/{a*(n-2)})*({a}x+{d})-{r}/({a*(n-1)}))}\\\\ &=&\\simplify[std]{1/({a}x+{d})^{n-1}*(({-m}/{(n-2)})*x+{-m*d*(n-1)-r*(n-2)}/{(n-2)*(n-1)*a})} \\end{eqnarray*} \\]
Hence \\[g(x)=\\simplify[std]{({-m}/{(n-2)})*x+{-m*d*(n-1)-r*(n-2)}/{(n-2)*(n-1)*a}}\\]

\n\t \n\t", "rulesets": {"std": ["all", "!collectNumbers", "fractionNumbers", "!noLeadingMinus"]}, "parts": [{"stepspenalty": 1.0, "prompt": "\n\t\t\t

$I=\\displaystyle \\int \\simplify[std]{({b}*x+{c})/(({a}*x+{d})^{n})} dx$

\n\t\t\t

You are given that \\[I=\\simplify[std]{g(x)*({a}x+{d})^{1-n}}+C\\] for a polynomial $g(x)$. You have to find $g(x)$.

\n\t\t\t

$g(x)=\\;$[[0]]

\n\t\t\t

Remember to input all numbers as integers or fractions.

\n\t\t\t

Click on Show steps to get help if you need it. You will lose 1 mark by doing so.

\n\t\t\t \n\t\t\t", "gaps": [{"notallowed": {"message": "

Do not input numbers as decimals, only as integers without the decimal point, or fractions

", "showstrings": false, "strings": ["."], "partialcredit": 0.0}, "checkingaccuracy": 0.001, "vsetrange": [0.0, 1.0], "vsetrangepoints": 5.0, "checkingtype": "absdiff", "answersimplification": "std", "marks": 3.0, "answer": "({-m}/{n-2})*x-{m*d*(n-1)+r*(n-2)}/{(n-2)*(n-1)*a}", "type": "jme"}], "steps": [{"prompt": "

One way to do this is by substitution, for example $y = \\simplify[std]{{a}*x+{d}}$.

", "type": "information", "marks": 0.0}], "marks": 0.0, "type": "gapfill"}], "statement": "\n\t

Find the following indefinite integral.

\n\t

Input all numbers as integers or fractions, not as decimals.

\n\t

Input the constant of integration as $C$.

\n\t \n\t", "variable_groups": [], "progress": "ready", "type": "question", "variables": {"a": {"definition": "random(2..5)", "name": "a"}, "c": {"definition": "m*d+r", "name": "c"}, "b": {"definition": "m*a", "name": "b"}, "d": {"definition": "random(1..5)", "name": "d"}, "s2": {"definition": "random(1,-1)", "name": "s2"}, "s1": {"definition": "random(1,-1)", "name": "s1"}, "m": {"definition": "s1*random(1..4)", "name": "m"}, "n": {"definition": "random(3..5)", "name": "n"}, "r": {"definition": "s2*random(1..5)", "name": "r"}}, "metadata": {"notes": "\n\t\t \t\t

2/08/2012:

\n\t\t \t\t

Added tags.

\n\t\t \t\t

Added description.

\n\t\t \t\t

Added a Step and message about Show steps included - losing 1 mark if used as it gives the formula for finding the integral. Increased marks to 3 for the question, so that can cope with losing a mark for using Show steps.

\n\t\t \t\t

Checked calculation. OK.

\n\t\t \t\t

Improved display in Advice.

\n\t\t \n\t\t", "description": "

Find the polynomial $g(x)$ such that $\\displaystyle \\int \\frac{ax+b}{(cx+d)^{n}} dx=\\frac{g(x)}{(cx+d)^{n-1}}+C$.

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Input all numbers as integers or fractions and not as decimals.

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$\\displaystyle f(x)=\\simplify[std]{({u}*x+{1-u}*(cos({c}x+{d})))*cos({u}*({a}x^2+{b})+{1-u}*(sin({c}x+{d})))}$

\n

Input $\\displaystyle \\int f(x)\\;dx$ here.

\n ", "checkingaccuracy": 0.001, "vsetrange": [0.0, 1.0], "vsetrangepoints": 5.0, "checkingtype": "absdiff", "answersimplification": "std", "marks": 1.0, "answer": "{u}/{2*a}*sin({a}x^2+{b})+{1-u}/{c}*sin(sin({c}x+{d}))+C", "type": "jme"}, {"notallowed": {"message": "

Input all numbers as integers or fractions and not as decimals.

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\n

$\\displaystyle f(x)=\\simplify[std]{({v}*x^2+{1-v}*(sin({c1}x+{d1})))*exp({v}*({a1}x^3)+{1-v}*(cos({c1}x+{d1})))}$

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Input $\\displaystyle \\int f(x)\\;dx$ here.

\n

 

\n ", "checkingaccuracy": 0.001, "vsetrange": [0.0, 1.0], "vsetrangepoints": 5.0, "checkingtype": "absdiff", "answersimplification": "std", "marks": 1.0, "answer": "(1/{3*a1}*{v}-{1}/{c1}*{1-v})*exp({v}*({a1}x^3)+{1-v}*(cos({c1}x+{d1})))+C", "type": "jme"}, {"notallowed": {"message": "

Input all numbers as integers or fractions and not as decimals.

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$\\displaystyle f(x)=\\simplify[std]{x^2*({1-u}*({a}+x^3)^({n}/2)+{u}*tan({a1}x^3+{d1}))}$

\n

Input $\\displaystyle \\int f(x)\\;dx$ here.

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Integrate the following functions $f(x)$.

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Input all numbers as integers or fractions and not as decimals.

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Make sure you include the constant of integration $C$.

\n ", "variable_groups": [], "progress": "ready", "type": "question", "variables": {"a": {"definition": "random(2..8)", "name": "a"}, "c": {"definition": "random(2..9)", "name": "c"}, "b": {"definition": "random(-9..9 except 0)", "name": "b"}, "d": {"definition": "random(-9..9 except 0)", "name": "d"}, "n": {"definition": "random(3..11#2)", "name": "n"}, "a1": {"definition": "random(2..9)", "name": "a1"}, "u": {"definition": "random(0,1)", "name": "u"}, "v": {"definition": "random(0,1)", "name": "v"}, "c1": {"definition": "random(2..9)", "name": "c1"}, "d1": {"definition": "random(2..9)", "name": "d1"}}, "metadata": {"notes": "

Note that we insist that $\\int \\frac{1}{x} \\;dx=\\ln(|u|)+C$ and $\\int \\tan(x) \\;dx=\\ln(|\\sec(u)|)+C$, so that users must input the absolute value as shown. This is crucial in the last part if the integral $\\int x^2 \\tan(x^3+a) \\;dx$ is to be evaluated.

", "description": "

Integration using subsitution

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Definite Integrals

"}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": [], "variables": {}, "tags": [], "statement": "

Find the following definite integrals

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Definite Integrals

", "parts": [{"checkvariablenames": false, "expectedvariablenames": [], "variableReplacements": [], "vsetrangepoints": 5, "prompt": "

$\\int_0^1\\cos(\\frac{\\pi t}{2})\\mathrm{dt}$.

\n

To write $\\pi$ in your answer simply write pi.

", "variableReplacementStrategy": "originalfirst", "checkingaccuracy": 0.001, "answer": "2/pi", "showCorrectAnswer": true, "checkingtype": "absdiff", "vsetrange": [0, 1], "marks": 1, "showFeedbackIcon": true, "type": "jme", "scripts": {}, "showpreview": true}, {"checkvariablenames": false, "expectedvariablenames": [], "variableReplacements": [], "vsetrangepoints": 5, "prompt": "

$\\int_0^1\\frac{e^z+1}{e^z+z}\\mathrm{dz}$.

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Express your answer using the natural log, ln().

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Hint: make a substition using the lower line.

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