Vector quantization is a technique used in (usually lossy) data compression. The basic idea is to code a multidimensional vector space into a sub-space with lower dimension. The lower-space vector requires less storage space and the data is thus compressed. The transformation into the sub-space is usually achieved through projection or by using a code-book.
... depend on x) to the expression to the left of "=", that will make it a perfect square trinomial of the form x2 + 2xy + y2. Since "2xy" in this case is (b/a)x, we must ...