Howtosignalprocessing
What is linear approximation of a system?
The linear approximation formula, as its name suggests, is a function that is used to approximate the value of a function at the nearest values of a fixed value. The linear approximation L(x) of a function f(x) at x = a is, L(x) = f(a) + f '(a) (x - a).
What is the best linear approximation of a function?
The tangent line is the best local linear approximation to a function at the point of tangency. Why is this so? If we look closely enough at any function (or look at it over a small enough interval) it begins to look like a line. The smaller the interval we consider the function over, the more it looks like a line.
