- #1
zigzag7
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Homework Statement
For z = x+iy find the relationship between x and y so that (Imz2) / z2 = -i
2. The attempt at a solution
I attempted this in a few different ways (i.e. looking at the exponential and trig forms of complex numbers)... I settled on simple FOIL which gave me the following:
(x+iy)^2 = x^2 + i2xy - y^2
The imaginary part is 2xy; so:
2xy / (x^2 + i2xy - y^2) = -i <-- from original problem
from here, multiplying -i by the denominator gives:
2xy = -ix^2 + 2xy + iy^2
Cancel out 2xy to get zero on the left side, and factor out i, leaving:
x^2 = y^2
However... this does not seem to produce any solutions resulting in -i.
For example, if x=2 and y=2, z^2 = 8i ... for x=-2 and y=2, z^2 = -8i ...
The problem is, there never seems to be a sign change for Im(z^2) over z^2.
Is this problem flawed, or am I missing something obvious...?