// Numbas version: exam_results_page_options {"name": "Partial differentiation", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"functions": {}, "ungrouped_variables": ["a", "c", "ch", "d", "m", "s5", "a1", "other", "b1", "c2", "c1", "b", "check", "d1"], "name": "Partial differentiation", "variablesTest": {"maxRuns": 100, "condition": ""}, "variable_groups": [], "parts": [{"showFeedbackIcon": true, "scripts": {}, "gaps": [{"checkingAccuracy": 0.001, "showFeedbackIcon": true, "expectedVariableNames": ["x", "y"], "answer": "(({a} * (x ^ 2)) + ({b} * x * y) + ({c} * (y ^ 2)))", "scripts": {}, "customMarkingAlgorithm": "", "type": "jme", "answerSimplification": "std", "failureRate": 1, "variableReplacements": [], "vsetRangePoints": 5, "vsetRange": [0, 1], "checkingType": "absdiff", "variableReplacementStrategy": "originalfirst", "unitTests": [], "showCorrectAnswer": true, "marks": 2, "checkVariableNames": true, "showPreview": true, "extendBaseMarkingAlgorithm": true}, {"checkingAccuracy": 0.001, "showFeedbackIcon": true, "expectedVariableNames": ["x", "y"], "answer": "((({b} / 2) * (x ^ 2)) + ({(2 * c)} * x * y) + {d})", "scripts": {}, "customMarkingAlgorithm": "", "type": "jme", "answerSimplification": "std", "failureRate": 1, "variableReplacements": [], "vsetRangePoints": 5, "vsetRange": [0, 1], "checkingType": "absdiff", "variableReplacementStrategy": "originalfirst", "unitTests": [], "showCorrectAnswer": true, "marks": 2, "checkVariableNames": true, "showPreview": true, "extendBaseMarkingAlgorithm": true}], "customMarkingAlgorithm": "", "type": "gapfill", "variableReplacements": [], "sortAnswers": false, "variableReplacementStrategy": "originalfirst", "unitTests": [], "prompt": "

Enter the partial derivatives here. Note if you want to enter a product of unknowns, such as $xy$ then you input the expression in the form x*y.

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$\\displaystyle { \\partial f \\over \\partial x}=$ [[0]]

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$\\displaystyle {\\partial f \\over \\partial y}=$ [[1]]

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\\[\\begin{eqnarray*} {\\partial f \\over \\partial x} &=&\\simplify[std]{(({a} * (x ^ 2)) + ({b} * x * y) + ({c} * (y ^ 2)))}\\\\ \\\\ \\partial f \\over \\partial y &=&\\simplify[std]{((({b} / 2) * (x ^ 2)) + ({(2 * c)} * x * y) + {d})} \\end{eqnarray*}\\]

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Find the stationary points of the function: $f(x,y)=a x ^ 3 + b x ^ 2 y + c y ^ 2 x + dy$ by choosing from a list of points.

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Answer the following questions about the function:

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\\[f(x,y)=\\simplify[std]{ ({a} / 3) * x ^ 3 + ({b} / 2) * x ^ 2 * y + {c} * y ^ 2 * x + {d} * y}\\]

\n ", "type": "question", "contributors": [{"name": "Bill Foster", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/6/"}, {"name": "Julie Crowley", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/113/"}]}]}], "contributors": [{"name": "Bill Foster", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/6/"}, {"name": "Julie Crowley", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/113/"}]}