Please solve the following

3. Use the definition of the derivative to find f' (3) if f(x) = x2 - 2x. 4. Let f (x) = ax2 + bx + c for constants a, b and c. (a) Show that the slope of the tangent to f at x = Xo is 2ax, + b (b) Find the equation of the tangent line to the graph of f at x = x