I recently posted articles on memoization of factorials and calculating sines and cosines with Taylor polynomials. It seems logical to combine the two principles and write a library to memoize the trigonometric values sine, cosine and tangent.

If you just need a few values then this approach is overkill, but some applications require very heavy use of trigonometry and so need all the optimization they can get. In particular 3D graphics consist of large numbers of triangles, the positioning and rendering of which requires some serious use of trigonometry.