Linear algebra is also useful for learning about inner product spaces and from them orthogonal basis functions, which is what you use for Fourier transforms and related methods (used in compression) and Spherical Harmonics (used.for global illumination). It's about decomposing complicated functions into linear combinations of simple functions. The idea is that functions can be thought of as vectors given a suitable set of basis functions and from then they can be combined or interpolated in a simple manner. Although the number of elements in the basis is infinite (for complete accuracy) the most important elements are the low frequency components and you can just forget about the higher frequency coefficients and still get a good approximation to the actual function.