Question
Find the square root of the following complex numbers: $8-15\text{i}$

Answer

Let $\text{z}=8-15\text{i}$ Then, $|\text{z}|=\sqrt{(8)^2+(-15)^2}$ $=\sqrt{64+225}$ $=\sqrt{289}$ $=17$ $\therefore\sqrt{8-15\text{i}}=\pm\Bigg\{\sqrt{\frac{17+8}{2}}-\text{i}\sqrt{\frac{17-8}{2}}\Bigg\} \ (\because\text{y}<0)$ $=\pm\Bigg\{\frac{5}{\sqrt{2}}-\text{i}\frac{3}{\sqrt{2}}\Bigg\}$ $=\pm\frac{1}{\sqrt{2}}\{5-3\text{i}\}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free