// Numbas version: finer_feedback_settings {"name": "Graphing: quartic", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"name": "Graphing: quartic", "tags": ["graphing", "Polynomial", "polynomial", "polynomials", "quartic", "sketching"], "metadata": {"description": "", "licence": "Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International"}, "statement": "
You are given the equation $y=\\simplify[all,fractionNumbers]{(x-{ee})(x-{d})({a}x^2+{b}x+{c})}$.
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", "stepsPenalty": "1", "steps": [{"type": "information", "useCustomName": false, "customName": "", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "An equation of the form $y=ax^4+bx^3+cx^2+dx+e$ is known as a quartic, or a quartic polynomial. If we expand $y=\\simplify[all,fractionNumbers]{(x-{ee})(x-{d})({a}x^2+{b}x+{c})}$ we will see it is a quartic.
"}], "minMarks": 0, "maxMarks": 0, "shuffleChoices": true, "displayType": "radiogroup", "displayColumns": 0, "showCellAnswerState": true, "choices": ["straight line
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"], "matrix": [0, "0", "0", 0, 0, "1"], "distractors": ["", "", "", "", "", ""]}, {"type": "1_n_2", "useCustomName": false, "customName": "", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "As we move to the far left of the graph of $y=\\simplify[all,fractionNumbers]{(x-{ee})(x-{d})({a}x^2+{b}x+{c})}$, the graph
", "stepsPenalty": "1", "steps": [{"type": "information", "useCustomName": false, "customName": "", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "What happens to the graph as you go far to the left or right is called the long term behaviour of a graph.
\nThe leading term (the term that includes the highest power) determines the long term behaviour of a polynomial.
\nBy expanding $y=\\simplify[all,fractionNumbers]{(x-{ee})(x-{d})({a}x^2+{b}x+{c})}$ we see that the leading term is $\\simplify[all,fractionNumbers]{{a}x^4}$.
\nAs we go far to the left of the graph $x$ is negative, and so $\\simplify[all,fractionNumbers]{{a}x^4}$ is negative. That is, the graph goes downwards. is positive. That is, the graph goes upwards.
\n"}], "minMarks": 0, "maxMarks": 0, "shuffleChoices": false, "displayType": "radiogroup", "displayColumns": 0, "showCellAnswerState": true, "choices": ["goes upwards.
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", "stepsPenalty": "1", "steps": [{"type": "information", "useCustomName": false, "customName": "", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "What happens to the graph as you go far to the left or right is called the long term behaviour of a graph.
\nThe leading term (the term that includes the highest power) determines the long term behaviour of a polynomial.
\nBy expanding $y=\\simplify[all,fractionNumbers]{(x-{ee})(x-{d})({a}x^2+{b}x+{c})}$ we see that the leading term is $\\simplify[all,fractionNumbers]{{a}x^4}$.
\nAs we go far to the right of the graph $x$ is positive, and so $\\simplify[all,fractionNumbers]{{a}x^4}$ is negative. That is, the graph goes downwards. is positive. That is, the graph goes upwards.
\n"}], "minMarks": 0, "maxMarks": 0, "shuffleChoices": false, "displayType": "radiogroup", "displayColumns": 0, "showCellAnswerState": true, "choices": ["goes upwards.
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"], "matrix": "rleading"}, {"type": "gapfill", "useCustomName": false, "customName": "", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "The $y$-intercept of the graph of $y=\\simplify[all,fractionNumbers]{(x-{ee})(x-{d})({a}x^2+{b}x+{c})}$ is $y=$[[0]].
", "stepsPenalty": "1", "steps": [{"type": "information", "useCustomName": false, "customName": "", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "The $y$-intercept is the value of $y$ when $x=0$, that is, the value of $y$ where the graph hits the $y$-axis. To find it, substitute $x=0$ into our equation:
\n\\[y=\\simplify[unitFactor,basic,fractionNumbers]{(0-{ee})(0-{d})({a}0^2+{b}0+{c})}=\\var{yint}.\\]
\n"}], "gaps": [{"type": "numberentry", "useCustomName": false, "customName": "", "marks": 1, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "{yint}", "maxValue": "{yint}", "correctAnswerFraction": true, "allowFractions": true, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": false, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}], "sortAnswers": false}, {"type": "gapfill", "useCustomName": false, "customName": "", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "The set of $x$-intercepts of the graph of $y=\\simplify[all,fractionNumbers]{(x-{ee})(x-{d})({a}x^2+{b}x+{c})}$ would be [[0]].
\nNote: If there are no intercepts, enter set()
\nIf there is only one intercept, say $x=5$, enter set(5)
\nIf there are two intercepts, say $x=-2$ and $x=1.5$, enter set(-2,1.5)
\nIf there are three intercepts, say $x=-2$, $x=1.5$ and $x=5$, enter set(-2,1.5,5)
\netc
\n", "stepsPenalty": "1", "steps": [{"type": "information", "useCustomName": false, "customName": "", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "The $x$-intercept is the value of $x$ when $y=0$, that is, the value of $x$ where the graph hits the $x$-axis. To find it, substitute $y=0$ into our equation:
\n\\[0=\\simplify[all,fractionNumbers]{(x-{ee})(x-{d})({a}x^2+{b}x+{c})} \\]
\nRecall, if a product is zero then one of the factors must be zero, therefore
\n\\[\\simplify[all,fractionNumbers]{x-{ee}=0}\\quad \\textrm{or}\\quad\\simplify[all,fractionNumbers]{x-{d}=0}\\quad \\text{or}\\quad\\simplify[all,fractionNumbers]{{a}x^2+{b}x+{c}=0}.\\]
\nSolving the first equation says that one of the $x$-intercepts is $x=\\var{ee}$.
\nSolving the second equation says that one of the $x$-intercepts is $x=\\var{d}$.
\nFor the third equation we will use the quadratic formula. Recall for $ax^2+bx+c=0$, the solutions (if they exist) are given by \\[x=\\dfrac{-b}{2a}\\pm\\dfrac{\\sqrt{b^2-4ac}}{2a}.\\]
\nFor the equation $y=\\simplify[all,fractionNumbers]{{a}x^2+{b}x+{c}}$, we have $b^2-4ac=\\simplify[all,fractionNumbers]{{b}^2-4{a}{c}}=\\var{disc}$ and so there are no more $x$-intercepts. is one more $x$-intercept: are two more $x$-intercepts:
\n| $x$ | \n$=$ | \n$\\dfrac{-b}{2a}\\pm\\dfrac{\\sqrt{b^2-4ac}}{2a}$ | \n
| \n | \n | \n |
| \n | $=$ | \n$\\simplify[basic,unitFactor,fractionNumbers]{{axis_x}}\\pm\\simplify[basic,unitFactor,fractionNumbers]{sqrt{{disc}}/({2*a})}$ | \n
| \n | \n | \n |
| \n | $=$ | \n$\\var{axis_x}$ $\\var{xint0}, \\, \\var{xint1}$ | \n
Given the degree of a polynomial is $4$, the maximum number of possible 'bends' or 'turns' in the graph is [[0]].
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