In Problems 1 4 use the definition f c lim AD f c h f c h to find the indicated derivative 1 f 1 if f x x 3 f 3 if f 1 1 5 s x 2x 1 7 r x 3x 4 9 f x ax bx c 11 f x x 2x 1 2 13 h x X 2 f 2 if f t 2x 4 f 4 if f s In Problems 5 22 use f x lim f x h f x h to find the derivative at x 6 f x ax 8 f x x x 1 10 f x x 12 g x x 1 14 S x