Saturday, October 13, 2018

complex analysis - Real and imaginary part of




Find the real and imaginary part of f(z)=(3y2+6ixy+3x2)e2(iy+x)




I came up with: Re=e2x(3y2cos(y)6xysin(y)+3x2cos(y))Im=ie2x(3y2sin(y)+6xycos(y)+3xsin(y))



Answer



Yes we can use that



e2(iy+x)=e2x(cos(2y)+isin(2y))



and therefore



(f(z))=(3y2+3x2)e2xcos(2y)6xye2xsin(2y)



(f(z))=6xye2xcos(2y)+(3y2+3x2)e2xsin(2y)




Recall that real part and imaginary parts are real numbers.


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