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## Homework Statement

What is the square root of z=-9

## Homework Equations

## The Attempt at a Solution

Is it possible of me to not use De'Moivre's theorem to solve this question??

Solution :

z= [itex]\sqrt{-9}[/itex]

z=[itex]\sqrt{9}[/itex] x [itex]\sqrt{}-1[/itex]

z=[itex]\pm3[/itex] i

Will this method be acceptable?? Is this still under the topic complex roots?