Question

Find the square of $\left(-6+30i\right)$ in the form of $\left(a+bi\right)$.

Answer 1

As we know that

$(a+ib{)}^2=a^2+b^2{i}^2+2ib$

Since, $i^2=-1$

Therefore,

$(a+ib{)}^2=a^2-b^2+2ib$

Similarly,

$(-6+30i{)}^2=36-900-360i$

$=-(864+360i)$