See 5.1 for background.
", "extensions": ["jsxgraph"], "tags": [], "variables": {"min": {"definition": "if(n[2]=0,3,2)", "description": "", "name": "min", "group": "part a", "templateType": "anything"}, "n": {"definition": "[0,0,random(0..3),random(2..4),random(1..4 except 2)]", "description": "", "name": "n", "group": "part a", "templateType": "anything"}, "c": {"definition": "shuffle([1,1,2,2,2])", "description": "", "name": "c", "group": "part a", "templateType": "anything"}, "marks": {"definition": "[2/min,2/min,if(n[2]=0,2/min,-2),n[3]*-2,n[4]*-2]", "description": "", "name": "marks", "group": "part a", "templateType": "anything"}, "b": {"definition": "shuffle([-1,-1,-2,-2,-3])", "description": "", "name": "b", "group": "part a", "templateType": "anything"}, "a": {"definition": "shuffle([1,1,1,1.5,1.5])", "description": "", "name": "a", "group": "part a", "templateType": "anything"}}, "parts": [{"warningType": "none", "displayType": "checkbox", "unitTests": [], "extendBaseMarkingAlgorithm": true, "showFeedbackIcon": true, "type": "m_n_2", "maxAnswers": 0, "customName": "", "choices": ["{plot(n[0],a[0],b[0],c[0])}
", "{plot(n[1],-a[1],b[1],c[1])}
", "{plot(n[2],a[2],b[2],c[2])}
", "{plot(n[3],a[3],b[3],c[3])}
", "{plot(n[4],a[4],b[4],c[4])}
"], "useCustomName": false, "displayColumns": 0, "adaptiveMarkingPenalty": 0, "shuffleChoices": true, "matrix": "marks", "showCorrectAnswer": true, "marks": 0, "prompt": "Which of the following look like graphs of a quadratic?
", "variableReplacementStrategy": "originalfirst", "minMarks": 0, "customMarkingAlgorithm": "", "maxMarks": 0, "minAnswers": "{min}", "variableReplacements": [], "showCellAnswerState": true, "scripts": {}}], "name": "Sketching graph: which graphs are quadratic graphs", "functions": {"plot": {"language": "javascript", "definition": "// This functions plots a cubic with a certain number of\n// stationary points and roots.\n// It creates the board, sets it up, then returns an\n// HTML div tag containing the board.\n\n\n// Max and min x and y values for the axis.\nvar x_min = -10;\nvar x_max = 10;\nvar y_min = -10;\nvar y_max = 10;\n\n\n// First, make the JSXGraph board.\nvar div = Numbas.extensions.jsxgraph.makeBoard(\n '300px',\n '300px',\n {\n boundingBox: [x_min,y_max,x_max,y_min],\n axis: false,\n showNavigation: false,\n grid: false,\n axis:false,\n }\n);\n\n\n\n// div.board is the object created by JSXGraph, which you use to \n// manipulate elements\nvar board = div.board; \n\n// create the x-axis and y-axis\nvar xaxis = board.create('line',[[0,0],[1,0]], { strokeColor: 'black', fixed: true});\n//var xticks = board.create('ticks',[xaxis,1],{\n// drawLabels: true,\n// label: {offset: [-4, -10]},\n// minorTicks: 0\n//});\n\n// create the y-axis\nvar yaxis = board.create('line',[[0,0],[0,1]], { strokeColor: 'black', fixed: true });\n\n\n\n\n// Plot the function.\n// board.create('functiongraph',\n// [function(x){ return (x-a)*(x-a)+b},x_min,x_max]);\n\n//Define function depending on value of n.\nswitch(n) {\n case 0:\n var f = function(x) {return a*(x-b)*(x-c); }\n break;\n \n case 1:\n var f = function(x) {return Math.log(x+a); }\n break;\n \n case 2:\n var f = function(x) {return a*x+b;}\n break;\n \n case 3:\n var f = function(x) {return Math.pow(2,x)*-a;}\n break;\n \n case 4:\n var f = function(x) {return a*x*(x-b)*(x-c);}\n break;\n \n}\n\n board.create('functiongraph', [f], {strokeWidth:3,strokeColor:'black'});\n\nreturn div;\n\n\n\n// Plot coordinates.\n// board.create('circle',[[x0,y0],0.1],{color:'red'});\n// board.create('text',[x0,y0+0.3,'A']);\n// board.create('circle',[[x1,y1],0.1],{color:'red'});\n// board.create('text',[x1,y1+0.3,'B']);\n// board.create('circle',[[x2,y2],0.1],{color:'red'});\n// board.create('text',[x2,y2+0.3,'C']);\n\nreturn div;", "parameters": [["n", "number"], ["a", "number"], ["b", "number"], ["c", "number"]], "type": "html"}}, "rulesets": {}, "metadata": {"description": "Five graphs are sketch. Task is to select those that look like parabolas/quadratics.
", "licence": "Creative Commons Attribution 4.0 International"}, "variable_groups": [{"name": "part a", "variables": ["a", "b", "c", "marks", "n", "min"]}], "contributors": [{"name": "Lovkush Agarwal", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/1358/"}]}]}], "contributors": [{"name": "Lovkush Agarwal", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/1358/"}]}