a. Find the derivative function f for the function f. b. Find an equation of the line tangent to the graph of f at (a, f(a)) for the given value of a. f(x) =2x - 9x + 10, a = 3 a. f' (x) = b. y=a. Use the Product Rule to find the derivative of the given function. b. Find the derivative by expanding the product first. f(x) = (x - 7)(5x + 2) a. Use the product rule to find the derivative of the function. Select the correct answer below and fill in the answer box(es) to complete your choice. O A. The derivative is x(5x + 2). O B. The derivative is (x - 7) ( ) + (5x + 2) ( O C. The derivative is (x - 7)(5x + 2) ( O D. The derivative is ( (x- 7). O E. The derivative is (x - 7)(5x + 2) + b. Expand the product. (x - 7)(5x + 2) = (Simplify your answer.) d Using either approach, dx -(x - 7)(5x + 2) =sin x COS X - 1 Use the trigonometric limits lim = 1 and/or lim =0 to evaluate the following limit. X-0 X X-+0 X sin 9x lim x-0 20x Select the correct choice below and, if necessary, fill in the answer box to complete your choice. sin 9x O A. lim (Type an integer or a simplified fraction.) X-+0 20x O B. The limit is undefined