// Numbas version: finer_feedback_settings {"name": "Adaptive marking: quadratic equation", "extensions": ["stats"], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"name": "Adaptive marking: quadratic equation", "variable_groups": [{"name": "Quadratic equation", "variables": ["roots", "a", "b", "xs", "ys"]}], "parts": [{"unitTests": [], "marks": 0, "sortAnswers": true, "variableReplacements": [], "showCorrectAnswer": true, "prompt": "
A quadratic function $f(x)$ goes through the points $(\\var{xs[0]},\\var{ys[0]})$, $(\\var{xs[1]},\\var{ys[1]})$ and $(\\var{xs[2]},\\var{ys[2]})$.
\nFind the two roots of $f$.
\nFirst root: [[0]]
\nSecond root: [[1]]
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\n$g(x) = $ [[0]]
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", "mustBeReducedPC": 0, "type": "numberentry", "mustBeReduced": false, "allowFractions": false, "customMarkingAlgorithm": "", "minValue": "mean(roots)", "extendBaseMarkingAlgorithm": true, "showFeedbackIcon": true, "variableReplacementStrategy": "originalfirst"}], "statement": "(This question doesn't make a lot of pedagogic sense, it just shows off how adaptive marking works)
", "ungrouped_variables": [], "tags": [], "extensions": ["stats"], "variablesTest": {"maxRuns": 100, "condition": ""}, "functions": {}, "preamble": {"js": "", "css": ""}, "metadata": {"description": "Give the student three points lying on a quadratic, and ask them to find the roots.
\nThen ask them to find the equation of the quadratic, using their roots. Error in calculating the roots is carried forward.
\nFinally, ask them to find the midpoint of the roots (just for fun). Error is carried forward again.
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", "templateType": "anything", "definition": "shuffle(-5..5 except [a,b])[0..3]", "group": "Quadratic equation"}, "a": {"name": "a", "description": "Least root of the quadratic equation
", "templateType": "anything", "definition": "roots[0]", "group": "Quadratic equation"}, "ys": {"name": "ys", "description": "y coordinates corresponding to the given x coordinates
", "templateType": "anything", "definition": "map((x-a)*(x-b),x,xs)", "group": "Quadratic equation"}}, "rulesets": {}, "contributors": [{"name": "Bill Foster", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/6/"}, {"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}]}]}], "contributors": [{"name": "Bill Foster", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/6/"}, {"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}]}