High Quality Content by WIKIPEDIA articles! In mathematics, the Fourier sine and cosine transforms are special cases of the continuous Fourier transform, arising naturally when attempting to transform odd and even functions, respectively.The Fourier sine transform is a special case of the continuous Fourier transform, arising naturally when attempting to transform an odd function. From the general Fourier transform noted above, if f(t) is assumed to be an odd function, the product f(t)cos t is also odd whilst the product f(t)sin t is an even function. The Fourier cosine transform is a special case of the continuous Fourier transform, arising naturally when attempting to transform an even function. From the general Fourier transform noted above, if f(t) is assumed to be an even function, the product f(t)cos t is also even whilst the product f(t)sin t is an odd function.