// Numbas version: finer_feedback_settings
{"name": "2.6.3 Circle radius and centre", "extensions": ["jsxgraph"], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"name": "2.6.3 Circle radius and centre", "tags": [], "metadata": {"description": "<p>Given a circle equation in the form (x-a)^2+(y-b)^2=r^2, write down the radius and centre coordinates.</p>", "licence": "Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International"}, "statement": "<p>Write down the radius and the coordinates of the centre of the following circle</p>\n<p style=\"padding-left: 40px;\">$\\var{equation}$</p>", "advice": "<p>The centre and radius can be read directly from the equation:</p>\n<p>Centre = ($\\var{centrex},\\var{centrey}$)</p>\n<p>Radius = $\\var{radius}$</p>", "rulesets": {}, "extensions": ["jsxgraph"], "builtin_constants": {"e": true, "pi,\u03c0": true, "i": true}, "constants": [], "variables": {"centrex": {"name": "centrex", "group": "The circle", "definition": "random(-9..9)", "description": "", "templateType": "anything", "can_override": false}, "centrey": {"name": "centrey", "group": "The circle", "definition": "random(-9..9)", "description": "", "templateType": "anything", "can_override": false}, "radius": {"name": "radius", "group": "The circle", "definition": "random(1..9)", "description": "", "templateType": "anything", "can_override": false}, "equation": {"name": "equation", "group": "The circle", "definition": "random(\n  simplify(expression(\"(x-\" + centrex + \")^2+(y-\"+ centrey + \")^2 = \" + radius*radius  ),\"all\"),\n  simplify(expression(\"(x-\" + centrex + \")^2+(y-\"+ centrey + \")^2 - \" + radius*radius + \"=0\"),\"all\")\n)", "description": "", "templateType": "anything", "can_override": false}, "graph": {"name": "graph", "group": "The graph", "definition": "jessiecode(\n  400,400,[{xmin},{ymax},{xmax},{ymin}],\"r={radius};Cx={centrex};Cy={centrey};\"+safe(\n  \"\"\"\n    C=point(Cx,Cy) <<color:'blue', name:'', snapToGrid: true>>;\n    circle(C,r) << strokeOpacity:0.3 >>;\n    implicitcurve('x^2+y^2-4');\n  \"\"\"),\n  [\n    \"axis\": true\n  ]\n)", "description": "", "templateType": "anything", "can_override": false}, "xmax": {"name": "xmax", "group": "The graph", "definition": "if(xmaxtemp-xmin > ymaxtemp-ymin,xmaxtemp,xmin+ymaxtemp-ymin)", "description": "", "templateType": "anything", "can_override": false}, "xmin": {"name": "xmin", "group": "The graph", "definition": "min(-1,centrex-radius-1)", "description": "", "templateType": "anything", "can_override": false}, "ymax": {"name": "ymax", "group": "The graph", "definition": "if(ymaxtemp-ymin > xmaxtemp-xmin,ymaxtemp,ymin+xmaxtemp-xmin)", "description": "", "templateType": "anything", "can_override": false}, "ymin": {"name": "ymin", "group": "The graph", "definition": "min(-1,centrey-radius-1)", "description": "", "templateType": "anything", "can_override": false}, "xmaxtemp": {"name": "xmaxtemp", "group": "The graph", "definition": "max(1,centrex+radius+1)", "description": "", "templateType": "anything", "can_override": false}, "ymaxtemp": {"name": "ymaxtemp", "group": "The graph", "definition": "max(1,centrey+radius+1)", "description": "", "templateType": "anything", "can_override": false}, "expr": {"name": "expr", "group": "The graph", "definition": "expression(\"x^2+y^2-4\")", "description": "", "templateType": "anything", "can_override": false}, "test": {"name": "test", "group": "The graph", "definition": "jsxgraph(400,400, [-4,4,4,-4], [\n    \"a\": [\"slider\", [[-3.5,2.5],[-1.5,2.5],[-3,0,3]], [\"id\": \"a\"]],\n    \"b\": [\"slider\", [[-3.5,1.5],[-1.5,1.5],[-3,0,3]], [\"id\": \"b\"]],\n    \"f\": [\"implicitcurve\", ['x^2+y^2-2.25'], [\"id\": \"f\"]]\n])", "description": "", "templateType": "anything", "can_override": false}}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": [], "variable_groups": [{"name": "The circle", "variables": ["centrex", "centrey", "radius", "equation"]}, {"name": "The graph", "variables": ["graph", "xmin", "ymin", "xmaxtemp", "ymaxtemp", "xmax", "ymax", "expr", "test"]}], "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": "<p>Centre = ( [[0]],[[1]] )</p>\n<p>Radius =&nbsp; [[2]]</p>", "gaps": [{"type": "numberentry", "useCustomName": true, "customName": "centre x", "marks": 1, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "{centrex}", "maxValue": "{centrex}", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": true, "customName": "centre y", "marks": 1, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "{centrey}", "maxValue": "{centrey}", "correctAnswerFraction": false, "allowFractions": false, "mustBeReduced": false, "mustBeReducedPC": 0, "displayAnswer": "", "showFractionHint": true, "notationStyles": ["plain", "en", "si-en"], "correctAnswerStyle": "plain"}, {"type": "numberentry", "useCustomName": true, "customName": "radius", "marks": 1, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": false, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "minValue": "{radius}", "maxValue": "{radius}", "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", "type": "question", "contributors": [{"name": "Merryn Horrocks", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/4052/"}], "resources": []}]}], "contributors": [{"name": "Merryn Horrocks", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/4052/"}]}