// Numbas version: exam_results_page_options {"name": "Marlon's copy of Finding the missing value of a constant in a polynomial, using the Factor Theorem ", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"variable_groups": [], "advice": "

Using the factor theorem, we know that if $(x-a)$ is a factor of a polynomial $f(x)$, then $f(a)=0$.

\n

We are given that $(\\simplify{x+{d}})$ is a factor of $g(x) = \\simplify{{w}*x^3+({w}{d}+{a}+{w}{b})*x^2+({a}{d}+{w}{b}{d}+{a}{b})*x+m}$.

\n

By the factor theorem, this means that $g(\\simplify{-{d}}) = 0$.

\n

Substituting $x=\\simplify{-{d}}$ into $g(x)$ gives

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\\[
\\begin{align}
g(\\simplify{-{d}}) &= \\simplify[all,!collectNumbers]{{coef_x3}+{coef_x2}+{coef_x}+m}\\\\
&=\\simplify{{coef_x3}+{coef_x2}+{coef_x}+m}.
\\end{align}
\\]

\n

Therefore, as $g(\\simplify{-{d}}) = 0$, we have

\n

\\[
\\begin{align}
\\simplify{{coef_x3}+{coef_x2}+{coef_x}+m}&=0\\\\
m&=\\simplify{-({coef_x3}+{coef_x2}+{coef_x})}.
\\end{align}
\\]

", "tags": ["Factor Theorem", "factor theorem", "polynomials", "Polynomials", "taxonomy"], "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": ["w", "a", "b", "d", "coef_x3", "coef_x2", "coef_x"], "extensions": [], "parts": [{"showCorrectAnswer": true, "variableReplacements": [], "gaps": [{"checkvariablenames": false, "checkingtype": "absdiff", "checkingaccuracy": 0.001, "type": "jme", "marks": "2", "variableReplacementStrategy": "originalfirst", "showFeedbackIcon": true, "expectedvariablenames": [], "variableReplacements": [], "vsetrangepoints": 5, "showCorrectAnswer": true, "answer": "{-({w}*({-d})^3+({w}*{d}+{a}+{w}*{b})*({-d})^2+({a}*{d}+{w}*{b}*{d}+{a}*{b})*{-d})}", "showpreview": true, "scripts": {}, "vsetrange": [0, 1]}], "prompt": "

Given that $(\\simplify{x+{d}})$ is a factor of $g(x) = \\simplify{{w}*x^3+({w}{d}+{a}+{w}{b})*x^2+({a}{d}+{w}{b}{d}+{a}{b})*x}+m$, find the value of $m$.

\n

$m =$ [[0]].

\n

", "type": "gapfill", "showFeedbackIcon": true, "marks": 0, "variableReplacementStrategy": "originalfirst", "scripts": {}}], "metadata": {"description": "

Given a factor of a cubic polynomial, factorise it fully by first dividing by the given factor, then factorising the remaining quadratic.

", "licence": "Creative Commons Attribution 4.0 International"}, "statement": "

The factor theorem states that if $f(x)$ is a polynomial and $f(p) = 0$, then $(x-p)$ is a factor of $f(x)$. 

", "functions": {}, "preamble": {"js": "", "css": ""}, "name": "Marlon's copy of Finding the missing value of a constant in a polynomial, using the Factor Theorem ", "rulesets": {}, "variables": {"coef_x2": {"description": "

Number obtained by putting x=-d into the second term of the equation.

", "group": "Ungrouped variables", "definition": "(w*d+a+w*b)*(-d)^2", "name": "coef_x2", "templateType": "anything"}, "coef_x3": {"description": "

Number obtained by putting x=-d into the first term of the equation.

", "group": "Ungrouped variables", "definition": "(w)*(-d)^3", "name": "coef_x3", "templateType": "anything"}, "b": {"description": "

Random number between -2 and 3 except 0 for creating polynomial.

", "group": "Ungrouped variables", "definition": "random(-2..3 except 0)", "name": "b", "templateType": "anything"}, "coef_x": {"description": "

Number obtained by putting x=-d into the third term of the equation.

", "group": "Ungrouped variables", "definition": "(a*d+w*b*d+a*b)*(-d)", "name": "coef_x", "templateType": "anything"}, "d": {"description": "

Used in creation of the polynomial.

", "group": "Ungrouped variables", "definition": "random(-2..2 except 0 except a except b)", "name": "d", "templateType": "anything"}, "a": {"description": "

Random number between -2 and 3, not including 0 for creating polynomial.

", "group": "Ungrouped variables", "definition": "random(-2..3 except 0)", "name": "a", "templateType": "anything"}, "w": {"description": "

Random number between 2,3,4.

", "group": "Ungrouped variables", "definition": "random(2,3,4)", "name": "w", "templateType": "anything"}}, "type": "question", "contributors": [{"name": "Marlon Arcila", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/321/"}]}]}], "contributors": [{"name": "Marlon Arcila", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/321/"}]}