Need help with these questions

1. If f(x) = 1.4x2 - 5x + 2.3, determine f' (x) using the definition of derivative. 2. Determine if the following limits exist and if they do, evaluate them. (a) lim Vx - 3 x-+9 2x - 18 (b) lim f(x) where f (x) = 2x - 7, x 5 10 x-10' Vx2 + 69 x > 10 3-x (c) lim x-+3 x2 + 2x - 15 X (d) lim x-+0 x2 + 3x +4 (e) ling (28 ) (x72) 3. Let f(x) = (x - 1)2(x+3)(2x -5). Determine intervals for which f(x) > 0 and f(x)