In Exercises 5-12, approximate the area under the graph of f(x) and above the x-axis using the following methods with n = 4. (a) Use left endpoints. (b) Use right endpoints. (c) Aver- age the answers in parts a and b. (d) Use midpoints. 5. f(x) = 2x + 5 6. f(x) = 3.x+2 7. f(x) = x + 4 8. f(x)=x from x = 1 to x = 5 9. f(x)=e+1 10. f(x) = e 2 11. f(x) = 12. f(x) == X 1 X from x = 2 to .x = from .x from x= 1 to x = 3 = from x = -2 to x = 2 from .x = from 4 x=-2 to .r = 2 1 from .r = from r = 0 to x = 4 from .r 1 to .r = 9 = from 1 to .x = 3 =