Yeah. Just square both sides.
Not always true...
I feel it can be +-3/2
Z1,Z2,Z3 forms an equilateral triangle with origin as centroid. So the difference in their arguments is 120°.
So how +3/2?
Oh sorry..i took -120 too and wrote cos -120=1/2
Make it Z' (and not Z) everywhere after I say the word consider...
@fog856 thanks bhai....