Question

Find the multiplicative inverse of $-i$

Answer 1

Given data: $z=-i$
Using the concept of multiplicative inverse.
$z^{-1}=\frac{1}{-i}$
Now, using rationalization method

$z^{-1}=\frac{1}{-i}\times \frac{i}{i}=\frac{i}{-(i{)}^2}=\frac{i}{1}$
$z^{-1}=i$