I am new to Mathematica. I try to do a DTFT using FourierSequenceTransform of sin()+cos(). The following are my attempts with different results. How to explain the difference
attempt 1:
dtft1=FourierSequenceTransform[Sin[1/2 Pi n], n, w]
dtft2=FourierSequenceTransform[Cos[1/4 Pi n],n, w]
This (dtft1+dtft2) gives the correct result
attempt 2:
dtftall=FourierSequenceTransform[Sin[1/2 Pi n]+Cos[1/4 Pi n], n, w]
The result of this line is 0
what went wrong ?