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thercias
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Homework Statement
Determine the real part, the imaginary part, and the absolute magnitude of the following expressions:
tanh(x-ipi/2)
cos(pi/2-iy)
Homework Equations
cos(x) = e^ix+e^-ix
tanh(x) = (1-e^-2x)/(1+e^-2x)
The Attempt at a Solution
for cos(pi/2-iy)= (e^(ipi/2-i^2(y))+e^(i^2(y)-ipi/2))/2
=0.5(e^ipi/2*e^-i^2y + e^i^2y*e^-ipi/2)
=0.5(ie^y+e^-y*-i)
=0.5i(e^y-e^-y)
therefore, imaginary = 0.5(e^y-e^-y)
and real = 0
for tanh(x-ipi/2) = (1-e^-2(x-ipi/2))/(1+e^-2(x-ipi/2))
after simplifying i get
(1+e^-2x)/(1-e^-2x)
so that ^ is the real part
and imaginary = 0
I'm not really sure if I am doing this right though, or if i have to somehow simplify these expressions to get the answer. If so, how would I solve the question?