// Numbas version: exam_results_page_options
{"name": "Deirdre's copy of Pattern matching - factorise an equation", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"statement": "", "variablesTest": {"condition": "", "maxRuns": 100}, "variable_groups": [], "parts": [{"showFeedbackIcon": true, "checkvariablenames": false, "showCorrectAnswer": true, "answer": "(x+{a})(x+{b})", "vsetrangepoints": 5, "type": "jme", "variableReplacements": [], "marks": "1", "variableReplacementStrategy": "originalfirst", "checkingtype": "absdiff", "scripts": {"mark": {"order": "after", "script": "// Parse the student's answer as a syntax tree\nvar studentTree = Numbas.jme.compile(this.studentAnswer,Numbas.jme.builtinScope);\n\n// Create the pattern to match against \n// we just want two sets of brackets, each containing two terms\n// or one of the brackets might not have a constant term\n// or for repeated roots, you might write (x+a)^2\nvar rule = Numbas.jme.compile('m_any( (x+??)(x+??), (x+??)^2, x*(x+??) )');\n\n// Check the student's answer matches the pattern. \nvar m = Numbas.jme.display.matchTree(rule,studentTree,true);\n// If not, take away marks\nif(!m) {\n  this.multCredit(0.5,'Your answer is not in the form $(\\\\dots)(\\\\dots)$.');\n}\n"}}, "showpreview": true, "checkingaccuracy": 0.001, "expectedvariablenames": [], "vsetrange": [0, 1], "prompt": "<p>Factorise $\\simplify{x^2+{a+b}x+{a*b}}$</p>"}], "extensions": [], "ungrouped_variables": ["a", "b"], "preamble": {"js": "", "css": ""}, "rulesets": {}, "tags": ["custom marking", "demo"], "metadata": {"licence": "Creative Commons Attribution 4.0 International", "description": "<p>The student is asked to factorise a quadratic $x^2 + ax + b$.&nbsp;A custom marking script uses pattern matching to ensure that the student's answer is of the form $(x+a)(x+b)$, $(x+a)^2$, or $x(x+a)$.</p>\n<p>To find the script, look in the&nbsp;<em>Scripts</em> tab of&nbsp;part <strong>a</strong>.</p>"}, "name": "Deirdre's copy of Pattern matching - factorise an equation", "functions": {}, "advice": "", "variables": {"b": {"name": "b", "templateType": "anything", "description": "", "group": "Ungrouped variables", "definition": "random(-5..5 except 0)"}, "a": {"name": "a", "templateType": "anything", "description": "", "group": "Ungrouped variables", "definition": "random(-5..5)"}}, "type": "question", "contributors": [{"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}, {"name": "Deirdre Casey", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/681/"}]}]}], "contributors": [{"name": "Christian Lawson-Perfect", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/7/"}, {"name": "Deirdre Casey", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/681/"}]}