// Numbas version: finer_feedback_settings {"name": "Irreducible quadratic factor partial fractions", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"ungrouped_variables": ["a", "b", "T", "R", "d", "c"], "tags": [], "metadata": {"licence": "Creative Commons Attribution 4.0 International", "description": "
Manipulation of algebraic fractions
"}, "variable_groups": [], "functions": {}, "statement": "Determine the partial fraction breakdown of the following expression:
\n\\(I(s)=\\frac{\\var{R}s+\\var{T}}{(s+\\var{a})(s^2+\\simplify{{b}*2}s+\\var{c})}\\)
\n", "variablesTest": {"maxRuns": 100, "condition": ""}, "variables": {"d": {"group": "Ungrouped variables", "description": "", "definition": "random(1..8#1)", "name": "d", "templateType": "randrange"}, "R": {"group": "Ungrouped variables", "description": "", "definition": "random(2..12#1)", "name": "R", "templateType": "randrange"}, "b": {"group": "Ungrouped variables", "description": "", "definition": "random(5..8#1)", "name": "b", "templateType": "randrange"}, "T": {"group": "Ungrouped variables", "description": "", "definition": "random(1..20#1)", "name": "T", "templateType": "randrange"}, "c": {"group": "Ungrouped variables", "description": "", "definition": "b^2+d^2", "name": "c", "templateType": "anything"}, "a": {"group": "Ungrouped variables", "description": "", "definition": "random(1..4#1)", "name": "a", "templateType": "randrange"}}, "name": "Irreducible quadratic factor partial fractions", "advice": "\n\\(I(s)=\\frac{\\var{R}s+\\var{T}}{(s+\\var{a})(s^2+\\simplify{{b}*2}s+\\var{c})}=\\frac{A}{s+\\var{a}}+\\frac{Bs+C}{(s^2+\\simplify{{b}*2}s+\\var{c})}\\)
\nMutiply across by the denominator \\((s+\\var{a})(s^2+\\simplify{{b}*2}s+\\var{c})\\) to get
\n\\(\\var{R}s+\\var{T}=A(s^2+\\simplify{{b}*2}s+{c})+Bs(s+\\var{a})+C(s+\\var{a})\\)
\nlet s = \\(-\\var{a}\\)
\n\\(\\simplify{-{R}*{a}+{T}}=\\simplify{({a}^2-2{a}*{b}+{c})}A\\)
\n\\(A=\\simplify{(-{R}*{a}+{T})/({a}^2-2*{a}*{b}+{c})}\\)
\nlet s = \\(0\\)
\n\\(\\var{T}=\\var{c}A+\\var{a}C\\)
\n\\(\\var{T}-\\var{c}(\\simplify{(-{R}*{a}+{T})/({a}^2-2*{a}*{b}+{c})})=\\var{a}C\\)
\n\\(C=\\simplify{({a}*{T}-2*{b}*{T}+{c}*{R})/({a^2}-2*{a}*{b}+{c})}\\)
\ncoefficient of \\(s^2 = \\var{R}\\)
\n\\(\\var{R}=A+B\\)
\n\\(B=\\var{R}-A\\)
\n\\(B=\\simplify{({R}*{a}-{T})/({a}^2-2*{a}*{b}+{c})}\\)
", "parts": [{"showCorrectAnswer": true, "variableReplacementStrategy": "originalfirst", "prompt": "Express your answer as a sum fractions:
\n\\(I(s) =\\) [[0]]
", "showFeedbackIcon": true, "marks": 0, "gaps": [{"checkvariablenames": false, "checkingtype": "absdiff", "showFeedbackIcon": true, "checkingaccuracy": 0.001, "answer": "(({T}-{a}*{R})/({c}-{b}*2*{a}+{a}^2))/(s+{a})+(({a}*{R}-{T})/({c}-2*{a}*{b}+{a}^2))s/(s^2+2*{b}s+{c})+({a}*{T}+{c}*{R}-{b}*2*{T})/({a}^2+{c}-2*{a}*{b})/(s^2+2*{b}s+{c})", "showpreview": true, "type": "jme", "showCorrectAnswer": true, "vsetrangepoints": 5, "variableReplacementStrategy": "originalfirst", "marks": "2", "vsetrange": [0, 1], "expectedvariablenames": [], "variableReplacements": [], "scripts": {}}], "type": "gapfill", "scripts": {}, "variableReplacements": []}], "preamble": {"css": "", "js": ""}, "rulesets": {}, "extensions": [], "type": "question", "contributors": [{"name": "Frank Doheny", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/789/"}]}]}], "contributors": [{"name": "Frank Doheny", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/789/"}]}