X For the following functions y = f(x), find f'(a) using Equation 3.1. 21. f(x) = 5x +4, a=-1 slo shes oud mort 22. f(x) = -7x+1, a=3 23. f(x) = x2+9x, a=2 24. f(x) = 3x2 - x+2, a =1 25. f(x) = Vx, a =4 26. f(x) = Vx - 2, a =6 27. f (x ) = -. 7, a = 2 28. f(x) = - x - 3: a=-1 29. f(x) = -2, a =1 ngent 30. f(x) = , a= 4 = a. For the following exercises, given the function y = f(x), a. find the slope of the secant line PQ for each point Q(x, f(x)) with x value given in the table. b. Use the answers from a. to estimate the value of the slope of the tangent line at P. c. Use the answer from b. to find the equation of the tangent line to f at point P