// Numbas version: exam_results_page_options {"name": "Maths Support: Hyperbolic functions", "navigation": {"onleave": {"action": "none", "message": ""}, "reverse": true, "allowregen": true, "preventleave": false, "browse": true, "showfrontpage": false, "showresultspage": "never"}, "duration": 0.0, "metadata": {"notes": "", "description": "
4 questions involving hyperbolic functions.
", "licence": "Creative Commons Attribution 4.0 International"}, "timing": {"timeout": {"action": "none", "message": ""}, "timedwarning": {"action": "none", "message": ""}}, "shufflequestions": false, "questions": [], "percentpass": 50.0, "allQuestions": true, "pickQuestions": 0, "type": "exam", "feedback": {"showtotalmark": true, "advicethreshold": 0.0, "showanswerstate": true, "showactualmark": true, "allowrevealanswer": true}, "showQuestionGroupNames": false, "question_groups": [{"name": "", "pickingStrategy": "all-ordered", "pickQuestions": 0, "questions": [{"name": "Hyperbolic Functions 1", "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": ["cosh", "hyperbolic equations", "hyperbolic functions", "logarithms", "quadratic equation", "sinh", "solving equations", "solving hyperbolic equations", "solving quadratic equation"], "advice": "\nUsing \\[\\cosh(x)=\\frac{e^x+e^{-x}}{2},\\;\\;\\;\\sinh(x)=\\frac{e^x-e^{-x}}{2}\\] and substituting into the equation gives:
\n\\[\\simplify[std]{{a1+b1}e^x+{a1-b1}e^(-x)={2*c1}}\\]
\nOn multiplying throughout by $e^x$, putting $y=e^x$ and tidying up the equation, we get:
\n\\[\\simplify[std]{{m1}* y ^ 2 + {m2} * y + {m3} = 0}\\]
\nThis quadratic has solutions:
\n\\[y = \\simplify[std]{{d1}/{al1}},\\;\\;\\;y=\\simplify[std]{{d2}/{be1}}\\]
\nSince $y=e^x$ we see that the solutions in terms of $x$ are:
\\[x = \\ln\\left(\\simplify[std]{{d1}/{al1}}\\right)=\\var{tans2},\\;\\;\\;x=\\ln\\left(\\simplify[std]{{d2}/{be1}}\\right)=\\var{tans3}\\]
both to 3 decimal places.
Hence the minimum solution is $x=\\var{ans2}$ and the maximum solution is $x=\\var{ans3}$.
\n ", "rulesets": {"std": ["all", "fractionNumbers", "!collectNumbers", "!noLeadingMinus"]}, "parts": [{"prompt": "\n \n \nInput the solutions for $x$ here:(if the solutions are the same input the number twice)
\n \n \n \nLeast solution = [[0]]
\n \n \n \nGreatest solution= [[1]]
\n \n \n \nInput both to 3 decimal places.
\n \n \n ", "gaps": [{"minvalue": "ans2-tol", "type": "numberentry", "maxvalue": "ans2+tol", "marks": 1.0, "showPrecisionHint": false}, {"minvalue": "ans3", "type": "numberentry", "maxvalue": "ans3", "marks": 1.0, "showPrecisionHint": false}], "type": "gapfill", "marks": 0.0}], "statement": "\nSolve the following equation for $x$.
\n\\[\\simplify[std]{{a1}cosh(x)+{b1}sinh(x)={c1}}\\]
\n ", "variable_groups": [], "progress": "ready", "type": "question", "variables": {"ans2": {"definition": "precround(ans12,3)", "name": "ans2"}, "ans3": {"definition": "precround(ans21,3)", "name": "ans3"}, "b1": {"definition": "s*(al1*be1-d1*d2)/2", "name": "b1"}, "d2": {"definition": "s6*random(1..8)", "name": "d2"}, "ans21": {"definition": "max(tans2,tans3)", "name": "ans21"}, "d1": {"definition": "if(al1*be1=d*d2,d+2,d)", "name": "d1"}, "al1": {"definition": "s5*random(2,4,6)", "name": "al1"}, "s6": {"definition": "random(1,-1)", "name": "s6"}, "s5": {"definition": 1.0, "name": "s5"}, "m1": {"definition": "round((a1+b1)/h)", "name": "m1"}, "m3": {"definition": "round((a1-b1)/h)", "name": "m3"}, "m2": {"definition": "round(-2*c1/h)", "name": "m2"}, "be1": {"definition": "s6*random(1..9)", "name": "be1"}, "tol": {"definition": 0.0, "name": "tol"}, "ans12": {"definition": "min(tans2,tans3)", "name": "ans12"}, "a2": {"definition": "(al1*be1+d1*d2)/2", "name": "a2"}, "c1": {"definition": "s*(d1*be1+d2*al1)/2", "name": "c1"}, "tans3": {"definition": "precround(ln(d2/be1),3)", "name": "tans3"}, "tans2": {"definition": "precround(ln(d1/al1),3)", "name": "tans2"}, "a1": {"definition": "abs(a2)", "name": "a1"}, "d": {"definition": "s5*random(2,4)", "name": "d"}, "h": {"definition": "gcf(gcf(abs(a1+b1),abs(a1-b1)),abs(2*c1))", "name": "h"}, "s": {"definition": "sign(a2)", "name": "s"}}, "metadata": {"notes": "\n \t\t2/07/2012:
\n \t\tAdded tags.
\n \t\tForced answers to be exactly to 3 decimal places, no tolerances via tolerance variable tol=0.
\n \t\tImproved display in Advice. Checked calculations.
\n \t\t19/07/2012:
\n \t\tAdded description. Rechecked calculations.
\n \t\t\n \t\t
25/07/2012:
\n \t\tAdded tags.
\n \t\tQuestion appears to be working correctly.
\n \t\t\n \t\t", "description": "
Solve for $x$: $a\\cosh(x)+b\\sinh(x)=c$. There are two solutions for this example.
", "licence": "Creative Commons Attribution 4.0 International"}, "showQuestionGroupNames": false, "question_groups": [{"name": "", "pickingStrategy": "all-ordered", "pickQuestions": 0, "questions": []}]}, {"name": "Hyperbolic Functions 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": {}, "ungrouped_variables": ["a", "b", "n", "a1", "a2", "b1", "b2"], "tags": ["Calculus", "Differentiation", "calculus", "chain rule", "cosh", "derivatives of hyperbolic functions", "differential", "differentiate", "differentiating hyperbolic functions", "differentiation", "hyperbolic functions", "product rule", "sinh", "tanh"], "preamble": {"css": "", "js": ""}, "advice": "Here is a table of the derivatives of some of the hyperbolic functions:
\n$f(x)$ | $\\displaystyle{\\frac{df}{dx}}$ |
---|---|
$\\sinh(bx)$ | \n$b\\cosh(bx)$ | \n
$\\cosh(bx)$ | \n$b\\sinh(bx)$ | \n
$\\tanh(bx)$ | \n$\\simplify{b*sech(bx)^2}$ | \n
$f(x)=\\simplify[std]{ x ^ {n} * sinh({a1} * x + {b1})}$
\nUse the product rule to obtain:
\\[\\frac{df}{dx} = \\simplify[std]{{n} * (x ^ {(n -1)}) * sinh({a1} * x + {b1}) + {a1} * (x ^ {n}) * Cosh({a1} * x + {b1})}\\]
$f(x)=\\tanh(\\simplify[std]{{a}x+{b}})$
\nUsing the table above we get:
\\[\\frac{df}{dx} = \\simplify[std]{{a}*sech({a}x+{b})^2}\\]
$f(x)=\\ln(\\cosh(\\simplify[std]{{a2}x+{b2}}))$
\nUsing the chain rule we find:
\n\\[\\frac{df}{dx} = \\simplify[std]{{a2} * tanh({a2} * x + {b2})}\\]
", "rulesets": {"std": ["all", "fractionNumbers", "!collectNumbers", "!noLeadingMinus"]}, "parts": [{"prompt": "\n$f(x)=\\simplify[std]{ x ^ {n} * sinh({a1} * x + {b1})}$
\n$\\displaystyle{\\frac{df}{dx}=\\;\\;}$[[0]]
\n ", "marks": 0, "gaps": [{"vsetrangepoints": 5, "expectedvariablenames": [], "checkingaccuracy": 0.001, "vsetrange": [0, 1], "showpreview": true, "marks": 1, "showCorrectAnswer": true, "answersimplification": "std", "scripts": {}, "answer": "{n} * (x ^ {(n -1)}) * sinh({a1} * x + {b1}) + {a1} * (x ^ {n}) * Cosh({a1} * x + {b1})", "checkingtype": "absdiff", "checkvariablenames": false, "type": "jme"}], "showCorrectAnswer": true, "scripts": {}, "type": "gapfill"}, {"prompt": "\n$f(x)=\\tanh(\\simplify[std]{{a}x+{b}})$
\n$\\displaystyle{\\frac{df}{dx}=\\;\\;}$[[0]]
\n ", "marks": 0, "gaps": [{"vsetrangepoints": 5, "expectedvariablenames": [], "checkingaccuracy": 0.001, "vsetrange": [0, 1], "showpreview": true, "marks": 1, "showCorrectAnswer": true, "answersimplification": "std", "scripts": {}, "answer": "{a}*sech({a}x+{b})^2", "checkingtype": "absdiff", "checkvariablenames": false, "type": "jme"}], "showCorrectAnswer": true, "scripts": {}, "type": "gapfill"}, {"prompt": "\n$f(x)=\\ln(\\cosh(\\simplify[std]{{a2}x+{b2}}))$
\n$\\displaystyle{\\frac{df}{dx}=\\;\\;}$[[0]]
\n ", "marks": 0, "gaps": [{"vsetrangepoints": 5, "expectedvariablenames": [], "checkingaccuracy": 0.001, "vsetrange": [0, 1], "showpreview": true, "marks": 1, "showCorrectAnswer": true, "answersimplification": "std", "scripts": {}, "answer": "{a2} * tanh({a2} * x + {b2})", "checkingtype": "absdiff", "checkvariablenames": false, "type": "jme"}], "showCorrectAnswer": true, "scripts": {}, "type": "gapfill"}], "statement": "Write down the derivatives of the following functions $f(x)$ .
\nNote that in order to input the square of a function such as $\\sinh(x)$ you have to input it as sinh(x))^2
, similarly for the other hyperbolic functions.
29/06/2012:
\n \t\tAdded and edited tags.
\n \t\t19/07/2012:
\n \t\tAdded description.
\n \t\tThere is also the problem of inputting functions of the form $xf(x)$ if $n=1$ or $2$ in the first question. So have reset $n$ to between $3$ and $7$. Otherwise would have to have an instruction here (perhaps depending on value of $n$).
\n \t\tChecked calculation.
\n \t\t23/07/2012:
\n \t\tAdded tags.
\n \t\t \n \t\tQuestion appears to be working correctly.
\n \t\t\n \t\t", "description": "
Differentiate the following functions: $\\displaystyle x ^ n \\sinh(ax + b),\\;\\tanh(cx+d),\\;\\ln(\\cosh(px+q))$
", "licence": "Creative Commons Attribution 4.0 International"}, "type": "question", "showQuestionGroupNames": false, "question_groups": [{"name": "", "pickingStrategy": "all-ordered", "pickQuestions": 0, "questions": []}]}, {"name": "Hyperbolic Functions 3", "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": {}, "ungrouped_variables": ["a", "b", "s2", "s1", "a1", "b1"], "tags": ["Calculus", "calculus", "cosh", "hyperbolic functions", "indefinite integration", "integral", "integrating hyperbolic functions", "integration", "integration by parts", "sinh"], "preamble": {"css": "", "js": ""}, "advice": "\\[\\int \\simplify[std]{cosh({a}x+{b})}\\;dx = \\frac{1}{\\var{a}}\\simplify[std]{ sinh({a}x+{b})}+C\\]
\nIntegrate by parts, so that
\n\\[\\begin{eqnarray*} \\int \\simplify[std]{x*sinh({a1}x+{b1})}\\;dx&=&\\int \\simplify[std]{x*d((cosh({a1}x+{b1}))/{a1})}\\\\ &=&\\frac{1}{\\var{a1}}\\simplify[std]{x*cosh({a1}x+{b1})}-\\frac{1}{\\var{a1}} \\int \\simplify[std]{cosh({a1}x+{b1})}\\;dx\\\\ &=&\\frac{1}{\\var{a1}}\\simplify[std]{x*cosh({a1}x+{b1})}-\\frac{1}{\\var{a1^2}}\\simplify[std]{sinh({a1}x+{b1})}+C \\end{eqnarray*} \\]
", "rulesets": {"std": ["all", "fractionNumbers", "!collectNumbers", "!noLeadingMinus"]}, "parts": [{"prompt": "\n$f(x)=\\simplify[std]{ cosh({a}x+{b})}$
\n$\\displaystyle{\\int f(x)\\;dx=\\;\\;}$[[0]]
\nYou must include the constant of integration as $C$.
\nInput all numbers as integers or fractions – not as decimals.
\n ", "marks": 0, "gaps": [{"notallowed": {"message": "Input all numbers as integers or fractions – not as decimals.
", "showStrings": false, "strings": ["."], "partialCredit": 0}, "vsetrangepoints": 5, "expectedvariablenames": [], "checkingaccuracy": 0.001, "vsetrange": [0, 1], "showpreview": true, "marks": 1, "showCorrectAnswer": true, "answersimplification": "std", "scripts": {}, "answer": "(1 / {a}) * sinh({a} * x + {b})+C", "checkingtype": "absdiff", "checkvariablenames": false, "type": "jme"}], "showCorrectAnswer": true, "scripts": {}, "type": "gapfill"}, {"prompt": "$f(x)=\\simplify[std]{x*sinh({a1}x+{b1})}$
\n$\\displaystyle{\\int f(x)\\;dx=\\;\\;}$[[0]]
\nInclude the constant of integration as $C$.
\nInput all numbers as integers or fractions – not as decimals.
\nPlease note that if you want to enter a function of the form $xf(x)$ then enter as x*f(x)
so that it's clear what you mean.
Input all numbers as integers or fractions – not as decimals.
", "showStrings": false, "strings": ["."], "partialCredit": 0}, "vsetrangepoints": 5, "expectedvariablenames": [], "checkingaccuracy": 0.001, "vsetrange": [0, 1], "showpreview": true, "marks": 1, "showCorrectAnswer": true, "answersimplification": "std", "scripts": {}, "answer": "(1 / {a1}) * x * Cosh({a1} * x + {b1}) - (1 / ({a1} ^ 2)) * Sinh({a1} * x + {b1})+C", "checkingtype": "absdiff", "checkvariablenames": false, "type": "jme"}], "showCorrectAnswer": true, "scripts": {}, "type": "gapfill"}], "statement": "\n \n \nIntegrate the following functions $f(x)$.
\n \n \n ", "variable_groups": [], "variablesTest": {"maxRuns": 100, "condition": ""}, "variables": {"a": {"definition": "random(2..9)", "templateType": "anything", "group": "Ungrouped variables", "name": "a", "description": ""}, "b": {"definition": "s1*random(1..9)", "templateType": "anything", "group": "Ungrouped variables", "name": "b", "description": ""}, "s2": {"definition": "random(1,-1)", "templateType": "anything", "group": "Ungrouped variables", "name": "s2", "description": ""}, "s1": {"definition": "random(1,-1)", "templateType": "anything", "group": "Ungrouped variables", "name": "s1", "description": ""}, "a1": {"definition": "random(2..9)", "templateType": "anything", "group": "Ungrouped variables", "name": "a1", "description": ""}, "b1": {"definition": "s2*random(1..9)", "templateType": "anything", "group": "Ungrouped variables", "name": "b1", "description": ""}}, "metadata": {"notes": "\n \t\t29/06/2012:
\n \t\t
Added and edited tags.
Added forbidden strings, the decimal point, to ensure fraction or integer input for numbers.
\n \t\tPut in $C$ as integration constant in both answers.
\n \t\t19/07/2012:
\n \t\tAdded instruction in second question so that an input of the form $x\\cosh$ is recognized.
\n \t\tAdded description.
\n \t\tChecked calculation.
\n \t\t23/07/2012:
\n \t\t \n \t\tAdded tags.
\n \t\t\n \t\t
\n \t\t
\n \t\t", "description": "
Find $\\displaystyle \\int\\cosh(ax+b)\\;dx,\\;\\;\\int x\\sinh(cx+d)\\;dx$
", "licence": "Creative Commons Attribution 4.0 International"}, "type": "question", "showQuestionGroupNames": false, "question_groups": [{"name": "", "pickingStrategy": "all-ordered", "pickQuestions": 0, "questions": []}]}, {"name": "Hyperbolic Functions 4", "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": {}, "ungrouped_variables": ["a", "b", "valacc", "val", "tol"], "tags": ["Calculus", "Steps", "arccosh", "calculus", "definite integration", "hyperbolic functions", "integral", "integration", "integration by substitution", "inverse hyperbolic functions", "standard integrals", "steps", "substitution"], "preamble": {"css": "", "js": ""}, "advice": "\nThis is the standard integral we use: \\[\\int \\frac{1}{\\sqrt{x^2-1}}\\;dx=\\simplify{arccosh(x)+C}\\]
\nFor this example if we make the substitution $\\displaystyle{x = \\simplify[std]{{b}v/{a}}}$ in our integral then we get:
\n\\[\\begin{eqnarray*} I &=&\\frac{1}{\\var{a}}\\int_{\\var{a}}^{\\var{2*a}}\\frac{1}{\\sqrt{v^2-1}}\\;dv\\\\ &=&\\frac{1}{\\var{a}}\\left[\\simplify{arccosh(v)}\\right]_{\\var{a}}^{\\var{2*a}}\\\\ &=&\\var{val} \\end{eqnarray*} \\] to 2 decimal places.
\n ", "rulesets": {"std": ["all", "fractionNumbers", "!collectNumbers", "!noLeadingMinus"]}, "parts": [{"stepsPenalty": 0, "prompt": "\n$I=\\;\\;$[[0]]
\nInput your answer to $2$ decimal places.
\nShow steps has some information on the standard integral you may need. You will lose no marks in looking at this.
\n ", "marks": 0, "gaps": [{"allowFractions": false, "marks": 3, "maxValue": "val+tol", "minValue": "val-tol", "correctAnswerFraction": false, "showCorrectAnswer": true, "scripts": {}, "type": "numberentry", "showPrecisionHint": false}], "showCorrectAnswer": true, "scripts": {}, "steps": [{"showCorrectAnswer": true, "prompt": "Use the standard integral:
\n\\[\\int \\frac{1}{\\sqrt{x^2-1}}\\;dx=\\simplify{arccosh(x)+C}\\]
", "scripts": {}, "type": "information", "marks": 0}], "type": "gapfill"}], "statement": "Use hyperbolic functions to find the value of:
\\[I=\\int_{\\var{b}}^{\\var{2*b}} \\left(\\frac{1}{\\sqrt{\\simplify[std]{{a^2}x^2-{b^2}}}}\\right)\\;dx\\]
30/06/2012:
\n \t\tAdded, edited tags
\n \t\tSlight change to prompt.
\n \t\tCould include standard integral in Show steps (once Show steps is available)
\n \t\t19/07/2012:
\n \t\tAdded description.
\n \t\tChanged Advice on the standard integral - so that it makes sense!
\n \t\tAdded Show steps information on the standard integral.
\n \t\tChecked calculation.
\n \t\tSet new tolerance variable tol=0 for the numeric input.
\n \t\t23/07/2012:
\n \t\t \n \t\tAdded tags.
\n \t\t \n \t\tSolution always requires arccosh(x) and not arcsinh(x) or arctanh(x). Is this on purpose?
\n \t\t\n \t\t
\n \t\t
Question appears to be working correctly.
\n \t\t\n \t\t
\n \t\t", "description": "
Find (hyperbolic substitution):
$\\displaystyle \\int_{b}^{2b} \\left(\\frac{1}{\\sqrt{a^2x^2-b^2}}\\right)\\;dx$