Solve the following questions. Write step by step solutions and justify your answers. 1) [20 Points] Use the limit definition to find the derivative of f(z) = V5 - 21 2) [20 Points] For the function g(x) = Vx - 2e + 5 cosx + 8kx A) Find the derivative of g(x), where k is a constant B) Find k such that g' (0) = 8. 3) [20 Points] Consider the function 4 - cos I f(z) = 2 - er A) Find f' (z). B) Write an equation of the tangent line to f(x) at the point (0, f(0))