The derivative of a function of f at x is given by f' (x) = lim f(acth) - f(2) h-0 h provided the limit exists. Use the definition of the derivative to find the derivative of f (2) = 2ac2 + 4a + 9. Enter the fully simplified expression for f (a + h) - f (a). Do not factor. f (act h) - f (2) f' (2)