let f be defined on [0,2$\pi$)
denote $f_x(y)=f(y-x)$
how do i go about showing $||f_x||_{L_p}=||f||_{L_p}$ for all p
i was trying to write out f in fourier series, and use the fact that the fourier coefficient of $f_x$ is $e^{inx}$ times the fourier coefficient of f. but i couldnt get anywhere.