SOLUTION: z=−3−4i Calulate the magnitude of the number and its square roots

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Question 1160230: z=−3−4i
Calulate the magnitude of the number and its square roots
Answer by ikleyn(52803) About Me  (Show Source):
You can put this solution on YOUR website!
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The magnitude = sqrt%28%28-3%29%5E2+%2B+%28-4%29%5E2%29 = sqrt%2825%29 = 5.


To find square roots, I will make this trick


    -3 - 4i = 1 - 4i -4 = complete the square = (1-2i)^2.


Therefore, the square roots of  (-3-4i)  are these two complex numbers


    (1-2i)  and  -(1-2i) = -1+2i.

Solved.