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To evaluate \\(\\sqrt{\\var{x}+\\var{y}j}\\) we must first express \\(Z=\\var{x}+\\var{y}j\\) in polar form.
\nThe modulus of \\(\\var{x}+\\var{y}j\\) = \\(\\sqrt{\\var{x}^2+(\\var{y})^2}=\\sqrt{\\simplify{{x^2}+{y}^2}}\\)
\nThe argument of the complex number is given by \\(\\theta=tan^{-1}\\left(\\frac{\\var{y}}{\\var{x}}\\right)=\\var{theta}\\)
\nAccording to De Moivre's theorem \\(Z^{\\var{n}}=|Z|^{\\var{n}}\\left(cos(\\var{n}*\\theta)+jsin(\\var{n}*\\theta)\\right)\\)
\n\\((\\simplify{{x}+{y}j})^\\var{n}=\\left(\\sqrt{\\simplify{{x^2}+{y}^2}}\\right)^{\\var{n}}\\left(cos(\\simplify{{n}*{theta}})+jsin(\\simplify{{n}*{theta}})\\right)\\)
\n=\\(\\simplify{{x2}+{y2}j}\\)
\n\\(A=\\var{x2}\\) and \\(B=\\var{y2}\\)
\n", "parts": [{"prompt": "\\(\\sqrt{\\var{x}+\\var{y}j}=\\pm(A+Bj)\\)
\nCalculate \\(A\\) and \\(B\\)
\n\n\\(A\\) = [[0]]
\n\\(B\\) = [[1]]
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"}, "ungrouped_variables": ["x", "y", "n", "theta", "mod", "x2", "y2"], "extensions": [], "variablesTest": {"maxRuns": 100, "condition": ""}, "rulesets": {}, "variables": {"y2": {"name": "y2", "description": "", "definition": "{mod}^{n}*sin({n}*{theta})", "templateType": "anything", "group": "Ungrouped variables"}, "y": {"name": "y", "description": "", "definition": "random(1..15#1)", "templateType": "randrange", "group": "Ungrouped variables"}, "mod": {"name": "mod", "description": "", "definition": "sqrt({x}^2+{y}^2)", "templateType": "anything", "group": "Ungrouped variables"}, "n": {"name": "n", "description": "", "definition": "0.5", "templateType": "number", "group": "Ungrouped variables"}, "x": {"name": "x", "description": "", "definition": "random(1..12#1)", "templateType": "randrange", "group": "Ungrouped variables"}, "x2": {"name": "x2", "description": "", "definition": "{mod}^{n}*cos({n}*{theta})", "templateType": "anything", "group": "Ungrouped variables"}, "theta": {"name": "theta", "description": "", "definition": "arctan({y}/{x})", "templateType": "anything", "group": "Ungrouped variables"}}, "type": "question", "contributors": [{"name": "Frank Doheny", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/789/"}]}]}], "contributors": [{"name": "Frank Doheny", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/789/"}]}