Find an efficient procedure to compute the discrete cosine & sin transforms using fft

Can't figure this out to save my life. Please help if possible

Consider the discrete cosine and sine transforms of a real sequence of numbers

Find an efficient procedure to compute using a Fast Fourier Transform of .

Can someone give me a hint/explain to me the way to go about doing this problem? I am completely lost. Thanks!

Re: Find an efficient procedure to compute the discrete cosine & sin transforms using

Quote:

Originally Posted by

**drewprogden** Can't figure this out to save my life. Please help if possible

Consider the discrete cosine and sine transforms of a real sequence of numbers

Find an efficient procedure to compute

using a Fast Fourier Transform of

.

Can someone give me a hint/explain to me the way to go about doing this problem? I am completely lost. Thanks!

What is the real part of the DFT of a real sequence? What is the imaginary part?

CB