Find the area of each shaded region please help i just need help with C and D

My math teacher told my class to "steal" a 6th grade fraction word problem from the internet, word problems? : -p requirements: only a 1 step word problem. needs to be complex.

Check all that apply. f is a function. f is a one-to-one function. c is a function. c is a one-to-one function.

Estimate the area under the curve f(x) = 16 - x^2 from x = 0 to x = 3 by using three inscribed (under the curve) rectangles. answer to the nearest integer.