$$$15625 + \frac{719413999 i}{1000000000}$$$の極形式
入力内容
$$$15625 + \frac{719413999 i}{1000000000}$$$の極形式を求めなさい。
解答
この複素数の標準形は $$$15625 + \frac{719413999 i}{1000000000}$$$ です。
複素数 $$$a + b i$$$ に対して、極形式は $$$r \left(\cos{\left(\theta \right)} + i \sin{\left(\theta \right)}\right)$$$ で与えられ、ここで $$$r = \sqrt{a^{2} + b^{2}}$$$ と $$$\theta = \operatorname{atan}{\left(\frac{b}{a} \right)}$$$。
$$$a = 15625$$$ と $$$b = \frac{719413999}{1000000000}$$$ が成り立つ。
したがって、$$$r = \sqrt{15625^{2} + \left(\frac{719413999}{1000000000}\right)^{2}} = \frac{\sqrt{244140625517556501957172001}}{1000000000}$$$。
また、$$$\theta = \operatorname{atan}{\left(\frac{\frac{719413999}{1000000000}}{15625} \right)} = \operatorname{atan}{\left(\frac{719413999}{15625000000000} \right)}$$$。
したがって、$$$15625 + \frac{719413999 i}{1000000000} = \frac{\sqrt{244140625517556501957172001}}{1000000000} \left(\cos{\left(\operatorname{atan}{\left(\frac{719413999}{15625000000000} \right)} \right)} + i \sin{\left(\operatorname{atan}{\left(\frac{719413999}{15625000000000} \right)} \right)}\right)$$$。
解答
$$$15625 + \frac{719413999 i}{1000000000} = \frac{\sqrt{244140625517556501957172001}}{1000000000} \left(\cos{\left(\operatorname{atan}{\left(\frac{719413999}{15625000000000} \right)} \right)} + i \sin{\left(\operatorname{atan}{\left(\frac{719413999}{15625000000000} \right)} \right)}\right) = \frac{\sqrt{244140625517556501957172001}}{1000000000} \left(\cos{\left(\left(\frac{180 \operatorname{atan}{\left(\frac{719413999}{15625000000000} \right)}}{\pi}\right)^{\circ} \right)} + i \sin{\left(\left(\frac{180 \operatorname{atan}{\left(\frac{719413999}{15625000000000} \right)}}{\pi}\right)^{\circ} \right)}\right)$$$A