Question

What is the square root by using imaginary number i for each of these.

-7
-15
-81
-50

I got -81 but I'm not so sure if it's correct I got
√ -81= 3i√ 9 but I'm not sure if this is correct of if I have to make the 9 a 3 as well.

Answer 1

\[\sqrt{-81}=\sqrt{81\times (-1)}=\sqrt{81}\sqrt{-1}=9i\]

Answer 2

the others are not perfect squares, so they will contain radicals
for example
\[\sqrt{-7}=\sqrt{7}i\]