// Numbas version: exam_results_page_options {"name": "Maria's copy of ZTest_Belinda's copy of Sketching functions", "extensions": ["jsxgraph"], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"tags": [], "preamble": {"css": "table#values th {\n background: none;\n text-align: center;\n}", "js": "function dragpoint_board() {\n var scope = question.scope;\n \n var a = scope.variables.a.value;\n var b = scope.variables.b.value;\n var c = scope.variables.c.value;\n\n \n var div = Numbas.extensions.jsxgraph.makeBoard('500px','500px',{boundingBox:[-2.5,11,2.5,-11],grid:true,withLabel:true});\n $(question.display.html).find('#dragpoint').append(div);\n\n var board = div.board;\n \n// ceeate axis labels\n \n var label1 = board.create('point',[2.1,0.2],{name:'X',size:-1});\n label1.setProperty({fixed:true});\n var label2 = board.create('point',[0,10.3],{name:'y',size:-1});\n label2.setProperty({fixed:true});\n \n \n \n //create draggable points\n\n\n var line0 = board.create('line',[[-2,0],[-2,1]],{visible: false});\n var np0 = board.create('glider',[-2,8.5,line0],\n {\n name:'A',\n size:5\n }\n );\n\n var line1 = board.create('line',[[-1,0],[-1,1]],{visible: false});\n var np1 = board.create('glider',[-1,8.5,line1],\n {\n name:'B',\n size:5\n }\n );\n \n var line2 = board.create('line',[[0,0],[0,1]],{visible: false});\n var np2 = board.create('glider',[0,8.5,line2],\n {\n name:'C',\n size:5,\n }\n );\n \n var line3 = board.create('line',[[1,0],[1,1]],{visible: false});\n var np3 = board.create('glider',[1,8.5,line3],\n {\n name:'D',\n size:5\n }\n );\n var line4 = board.create('line',[[2,0],[2,1]],{visible: false});\n var np4 = board.create('glider',[2,8.5,line4],\n {\n name:'E',\n size:5\n }\n );\n \n //shorthand to evaluate a mathematical expression to a number\n function evaluate(expression) {\n try {\n var val = Numbas.jme.evaluate(expression,question.scope);\n return Numbas.jme.unwrapValue(val);\n }\n catch(e) {\n // if there's an error, return no number\n return NaN;\n }\n }\n \n // set up points array\n var num_points = 5;\n var points = [np0, np1, np2, np3, np4];\n \n \n // this function sets up the i^th point\n function make_point(i) {\n \n var point = points[i];\n \n var x=point[0];\n var y=point[1];\n \n // the contents of the input box for this point\n var xstudentAnswer = question.parts[0].gaps[i].display.studentAnswer;\n\n \n // when the student drags the point, update the gapfill input\n point.on('drag',function(){\n var x = Numbas.math.niceNumber(point.X());\n var y = Numbas.math.niceNumber(point.Y());\n var diff = y-(a*x*x+b*x+c);\n xstudentAnswer(diff);\n });\n \n }\n \n // create each point\n for(var i=0;i", "variableReplacements": [], "extendBaseMarkingAlgorithm": true, "sortAnswers": false, "showCorrectAnswer": true, "scripts": {}, "type": "gapfill", "unitTests": []}], "name": "Maria's copy of ZTest_Belinda's copy of Sketching functions", "variables": {"c": {"description": "

The function is f(x)=ax^2+bx+c.

", "group": "Ungrouped variables", "definition": "random(-9..9)", "templateType": "anything", "name": "c"}, "a": {"description": "

The function is f(x)=ax^2+bx+c.

", "group": "Ungrouped variables", "definition": "random(2..5)", "templateType": "anything", "name": "a"}, "b": {"description": "

The function is f(x)=ax^2+bx+c.

", "group": "Ungrouped variables", "definition": "random(-5..5 except 0)", "templateType": "anything", "name": "b"}}, "extensions": ["jsxgraph"], "ungrouped_variables": ["a", "b", "c"], "statement": "

By dragging the points A, B, C, D and E, construct the graph of the function $y=\\simplify[all]{{a}*x^2+{b}*x+{c}}$.

\n

Note that in order to be marked correct, the points need to be within 0.2 of their correct $y$-values.

\n

Also note that you have to drag each of the points in order to be able to submit your answer.

", "advice": "

The correct graph is shown below.

\n

{graph(a,b,c)}

", "variablesTest": {"condition": "4*a+2*b+c<=10 and 4*a+2*b+c>=-10 and 4*a-2*b+c<=10 and 4*a-2*b+c>=-10 and (-b/(2*a) < -2 or -b/(2*a) >2 or (-(b^2-4*a*c)/(4*a) <= 10 and -(b^2-4*a*c)/(4*a) >= -10))", "maxRuns": "200"}, "metadata": {"description": "", "licence": "Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International"}, "type": "question", "contributors": [{"name": "Matthew Mears", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/1688/"}, {"name": "Belinda Schwerin", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/2286/"}, {"name": "Maria Aneiros", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/3388/"}]}]}], "contributors": [{"name": "Matthew Mears", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/1688/"}, {"name": "Belinda Schwerin", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/2286/"}, {"name": "Maria Aneiros", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/3388/"}]}