Fourier transform of $|2\cos(2x)|$

138 Views Asked by At

I want to know what is the Fourier transform of $|2\cos(2x)|$

I know how to calculate the Fourier transform of $2\cos(2x)$ but absolute value bothers me.

I write it in another form --> $$|e^{-2ix} + e^{2ix} | $$ but it doesn't help me.

any help is much appreciated.