What is the linearization of a function f(x) at a point x = a, and how is it used to approximate values of the function near a?
The linearization of f(x) at x = a is L(x) = f(a) + f'(a)(x - a). It is used to approximate values of f(x) near a by replacing the function with its tangent line at that point, making calculations simpler and providing accurate estimates for values close to a.