// Numbas version: finer_feedback_settings {"name": "Luis's copy of The distance between two complex numbers", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"question_groups": [{"name": "", "pickingStrategy": "all-ordered", "questions": [], "pickQuestions": 0}], "statement": "
Find the distance between the following complex numbers, leaving your answer in decimal form to 3 decimal places:
", "variablesTest": {"maxRuns": 100, "condition": ""}, "tags": ["checked2015", "complex numbers", "distance between complex numbers", "mas1602", "MAS1602", "modulus", "modulus of a complex number", "modulus of complex numbers"], "metadata": {"notes": "15/07/2015:
\nAdded tags.
\n5/07/2012:
\nAdded tags.
\nPerhaps more steps are needed in the solutions? It isn't explained how to find the modulus of the complex number. Explanation included in Advice.
\nQuestion appears to be working correctly.
\n13/07/2012:
\nSet new variable tol=0 for all numeric input.
", "description": "Finding the distance between two complex numbers using the modulus of their difference. Three parts.
", "licence": "Creative Commons Attribution 4.0 International"}, "parts": [{"variableReplacements": [], "gaps": [{"variableReplacements": [], "minValue": "ans1-tol", "maxValue": "ans1+tol", "allowFractions": false, "marks": 1, "type": "numberentry", "showCorrectAnswer": true, "scripts": {}, "showPrecisionHint": false, "variableReplacementStrategy": "originalfirst", "correctAnswerFraction": false}], "marks": 0, "type": "gapfill", "showCorrectAnswer": true, "scripts": {}, "prompt": "\n \n \nFind the distance between $\\var{z1}$ and $\\var{z2}$.
\n \n \n \nDistance = [[0]]
\n \n \n ", "variableReplacementStrategy": "originalfirst"}, {"variableReplacements": [], "gaps": [{"variableReplacements": [], "minValue": "ans2-tol", "maxValue": "ans2+tol", "allowFractions": false, "marks": 1, "type": "numberentry", "showCorrectAnswer": true, "scripts": {}, "showPrecisionHint": false, "variableReplacementStrategy": "originalfirst", "correctAnswerFraction": false}], "marks": 0, "type": "gapfill", "showCorrectAnswer": true, "scripts": {}, "prompt": "\n \n \nFind the distance between $\\var{z3}$ and $\\var{z4}$.
\n \n \n \nDistance = [[0]]
\n \n \n ", "variableReplacementStrategy": "originalfirst"}, {"variableReplacements": [], "gaps": [{"variableReplacements": [], "minValue": "ans3-tol", "maxValue": "ans3+tol", "allowFractions": false, "marks": 1, "type": "numberentry", "showCorrectAnswer": true, "scripts": {}, "showPrecisionHint": false, "variableReplacementStrategy": "originalfirst", "correctAnswerFraction": false}], "marks": 0, "type": "gapfill", "showCorrectAnswer": true, "scripts": {}, "prompt": "\n \n \nFind the distance between $\\var{z5}$ and $\\var{z6}$.
\n \n \n \nDistance = [[0]]
\n \n \n ", "variableReplacementStrategy": "originalfirst"}], "variables": {"z2": {"name": "z2", "definition": "a2+b2*i", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "s1": {"name": "s1", "definition": "random(1,-1)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "t2": {"name": "t2", "definition": "s5*random(1..9)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "ans3": {"name": "ans3", "definition": "precround(abs(z5-z6),3)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "s7": {"name": "s7", "definition": "random(1,-1)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "a1": {"name": "a1", "definition": "s1*random(1..9)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "a2": {"name": "a2", "definition": "s2*random(1..9)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "z5": {"name": "z5", "definition": "a4+b4*i", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "t3": {"name": "t3", "definition": "s7*random(1..9)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "a3": {"name": "a3", "definition": "s1*random(1..9)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "s5": {"name": "s5", "definition": "random(1,-1)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "c4": {"name": "c4", "definition": "s4*random(1..9)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "b3": {"name": "b3", "definition": "if(d2=t2,t2+random(1..4),t2)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "z4": {"name": "z4", "definition": "a3+b3*i", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "z1": {"name": "z1", "definition": "a1+b1*i", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "b1": {"name": "b1", "definition": "if(b2=t1,t1+random(1..4),t1)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "a4": {"name": "a4", "definition": "s6*random(1..9)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "ans1": {"name": "ans1", "definition": "precround(abs(z1-z2),3)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "s6": {"name": "s6", "definition": "random(1,-1)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "c2": {"name": "c2", "definition": "s6*random(1..9)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "t1": {"name": "t1", "definition": "s4*random(1..9)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "tol": {"name": "tol", "definition": "0.001", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "z6": {"name": "z6", "definition": "c4+d4*i", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "d4": {"name": "d4", "definition": "if(b4=t3,t3+random(1..4),t3)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "s4": {"name": "s4", "definition": "random(1,-1)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "ans2": {"name": "ans2", "definition": "precround(abs(z3-z4),3)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "d2": {"name": "d2", "definition": "s7*random(1..9)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "s3": {"name": "s3", "definition": "random(1,-1)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "b2": {"name": "b2", "definition": "s5*random(1..9)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "s2": {"name": "s2", "definition": "random(1,-1)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "z3": {"name": "z3", "definition": "c2+d2*i", "group": "Ungrouped variables", "description": "", "templateType": "anything"}, "b4": {"name": "b4", "definition": "s1*random(1..9)", "group": "Ungrouped variables", "description": "", "templateType": "anything"}}, "name": "Luis's copy of The distance between two complex numbers", "advice": "\n \n \nThe distance D between two complex numbers $z_1=a+bi$ and $z_2=c+di$ is given by the modulus of the difference i.e.
\\[D=|z_1-z_2| = |(a-c)+(b-d)i|=\\sqrt{(a-c)^2+(b-d)^2}\\]
Applying to the questions we have:\t\t\t\t\t
a) \\[ \\begin{eqnarray*} D&=&|(\\var{z1})-(\\var{z2})|\\\\\n \n &=&|\\var{z1-z2}|\\\\\n \n &=& \\var{abs(z1-z2)}\\\\\n \n &=&\\var{ans1}\n \n \\end{eqnarray*} \\] to 3 decimal places.
b) \\[ \\begin{eqnarray*} D&=&|(\\var{z3})-(\\var{z4})|\\\\\n \n &=&|\\var{z3-z4}|\\\\\n \n &=& \\var{abs(z3-z4)}\\\\\n \n &=&\\var{ans2}\n \n \\end{eqnarray*} \\] to 3 decimal places.
\n \n \n \nc) \\[ \\begin{eqnarray*} D&=&|(\\var{z5})-(\\var{z6})|\\\\\n \n &=&|\\var{z5-z6}|\\\\\n \n &=& \\var{abs(z5-z6)}\\\\\n \n &=&\\var{ans3}\n \n \\end{eqnarray*} \\] to 3 decimal places.
\n \n \n ", "preamble": {"js": "", "css": ""}, "showQuestionGroupNames": false, "ungrouped_variables": ["ans1", "ans2", "ans3", "b4", "b1", "b2", "b3", "d4", "d2", "s3", "s2", "s1", "s7", "s6", "s5", "s4", "z2", "tol", "z3", "a1", "a3", "a2", "a4", "z4", "z5", "z6", "z1", "c2", "c4", "t2", "t3", "t1"], "type": "question", "functions": {}, "rulesets": {"std": ["all", "!collectNumbers", "fractionNumbers", "!noLeadingMinus"]}, "variable_groups": [], "contributors": [{"name": "Newcastle University Mathematics and Statistics", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/697/"}, {"name": "Luis Hernandez", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/2870/"}]}]}], "contributors": [{"name": "Newcastle University Mathematics and Statistics", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/697/"}, {"name": "Luis Hernandez", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/2870/"}]}