Question

Find the square root of : -
i) z = -16 + 30 i

Answer 1

$z=-16+30i=-16+2\left(15i\right)$

$=9-25+2\left(3\right)\left(5i\right)$

$=3^2+(5i{)}^2+2(3\left)\right(5i)$

$=(3+5i{)}^2$

$\sqrt{z}=3+5i$ or $-3-5i$