3. (Spoints) Given f(x) = 6 4x + x2, a) Find the equation of the tangent line to f (x) at x=1. b) Sketch a graph of the f (x) function and the tangent line on the same set of axis. 4. (6 points) Given f (x) = 2 3x2, using the limit denition of derivative, nd f '(x) . 5. (9 points) Find the domain of the following functions (in interval notation and in exact values)