// Numbas version: finer_feedback_settings
{"name": "Quadratic Formula", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"name": "Quadratic Formula", "tags": [], "metadata": {"description": "
This question tests the students ability to factorise simple quadratic equations (where the coefficient of the x^2 term is 1) and use the factorised equation to solve the equation when it is equal to 0.
", "licence": "Creative Commons Attribution 4.0 International"}, "statement": "To solve a quadratic equation of the form $ax^2+bx+c=0$ when we cant find the factors, we can instead use the formula:
\n\\[x=\\frac{-b\\pm\\sqrt{b^2-4ac}}{2a},\\space \\text{når}\\space b^2-4ac\\geq0\\text{.}\\]
\nThe equation $ax^2+bx+c$ has roots $x=x_{1}$ and$x=x_{2}$ which lead to factors $(x-x_{1})(x-x_{2}).$
", "advice": "", "rulesets": {}, "extensions": [], "builtin_constants": {"e": true, "pi,\u03c0": true, "i": true, "j": false}, "constants": [], "variables": {"b1": {"name": "b1", "group": "last q", "definition": "random(2..6)", "description": "", "templateType": "anything", "can_override": false}, "t4": {"name": "t4", "group": "Ungrouped variables", "definition": "t2*random(-4..6 except 0)", "description": "", "templateType": "anything", "can_override": false}, "b": {"name": "b", "group": "Part A ", "definition": "-a", "description": "", "templateType": "anything", "can_override": false}, "b3": {"name": "b3", "group": "last q", "definition": "random(1..10)", "description": "", "templateType": "anything", "can_override": false}, "v3": {"name": "v3", "group": "Part A ", "definition": "v5*v6+v4", "description": "", "templateType": "anything", "can_override": false}, "v2": {"name": "v2", "group": "Part A ", "definition": "random(2..6 except [v1,-v1])", "description": "", "templateType": "anything", "can_override": false}, "v6": {"name": "v6", "group": "Part A ", "definition": "random(2..10 except v5 -v5)", "description": "", "templateType": "anything", "can_override": false}, "v4": {"name": "v4", "group": "Part A ", "definition": "random(2..20)", "description": "", "templateType": "anything", "can_override": false}, "t1": {"name": "t1", "group": "Ungrouped variables", "definition": "random(1..2)", "description": "", "templateType": "anything", "can_override": false}, "t2": {"name": "t2", "group": "Ungrouped variables", "definition": "random(1..4)", "description": "", "templateType": "anything", "can_override": false}, "r2": {"name": "r2", "group": "Part B", "definition": "random(r1..9 except 0 r1 -r1)", "description": "", "templateType": "anything", "can_override": false}, "b4": {"name": "b4", "group": "last q", "definition": "random(-8..8 except 0)", "description": "", "templateType": "anything", "can_override": false}, "v5": {"name": "v5", "group": "Part A ", "definition": "random(-8..10 except 0 v1 v2)", "description": "", "templateType": "anything", "can_override": false}, "b2": {"name": "b2", "group": "last q", "definition": "random(1..6)", "description": "", "templateType": "anything", "can_override": false}, "a": {"name": "a", "group": "Part A ", "definition": "random(2..10)", "description": "", "templateType": "anything", "can_override": false}, "v1": {"name": "v1", "group": "Part A ", "definition": "random(-9..10 except 0)", "description": "", "templateType": "anything", "can_override": false}, "r1": {"name": "r1", "group": "Part B", "definition": "random(-9..7 except 0..1)", "description": "", "templateType": "anything", "can_override": false}, "t3": {"name": "t3", "group": "Ungrouped variables", "definition": "random(t4*t1/t2..10 #1 except 0)", "description": "", "templateType": "anything", "can_override": false}}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": ["t1", "t2", "t3", "t4"], "variable_groups": [{"name": "Part A ", "variables": ["v6", "v5", "v4", "v3", "v2", "v1", "a", "b"]}, {"name": "Part B", "variables": ["r2", "r1"]}, {"name": "last q", "variables": ["b1", "b2", "b3", "b4"]}], "functions": {}, "preamble": {"js": "", "css": ""}, "parts": [{"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": "Given the equation $\\simplify{x^2 +{r1+r2}x+{r1*r2}}=0\\text{.}$
\nUse the quadratic formula to find the roots $x_1$ and $x_2$, where $x_1<x_2$
\n\n$x_1=$ [[0]] (NB: $x_1<x_2$)
\n$x_2=$ [[1]]
", "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": "-r2", "maxValue": "-r2", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": false, "customName": "", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "-r1", "maxValue": "-r1", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}], "sortAnswers": false}], "partsMode": "all", "maxMarks": 0, "objectives": [], "penalties": [], "objectiveVisibility": "always", "penaltyVisibility": "always", "contributors": [{"name": "Blathnaid Sheridan", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/447/"}, {"name": "Ida Landg\u00e4rds", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/2336/"}]}]}], "contributors": [{"name": "Blathnaid Sheridan", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/447/"}, {"name": "Ida Landg\u00e4rds", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/2336/"}]}