Approximate the area under the graph of f(x) and above the x-axis with rectangles, using the following methods

Approximate the area under the graph of f(x) and above the x-axis with rectangles, using the following methods with n = 4. f(x) = 2x +4 from x = 2 to x = 4 a. Use left endpoints. b. Use right endpoints. c. Average the answers in parts a and b. d. Use midpoints. a. The area, approximated using the left endpoints, is b. The area, approximated using the right endpoints, is c. The average of the answers in parts a and b is d. The area, approximated using the midpoints, is