Let f(x) = x 3 + 1: (a) Using only the limit denition of the derivative, nd a simple formula for f 0 (a) at any point where x = a: You must show all work. No credit will be given for using the Power Rule for derivatives. f 0 (a) = (b) Find the three equations of the tangent lines at the point where x = 0; 1; 2: Lf;0(x) = Lf;1(x) = Lf;2(x) =