### Home > CALC > Chapter 3 > Lesson 3.3.2 > Problem 3-106

3-106.

Examine the Riemann sum below for the area under

*f*(*x*). Homework Help ✎

How many rectangles were used?

If the area being approximated is A(

*f*,*a*≤*x*≤*b*), what are*a*and*b*?

Notice that the index starts at 0 and ends at 11.

*a* = 3 is easy to spot in a Riemann sum. Now find the end-value, *b*.

General form of a left-endpoint Riemann sum:

You already computed how many rectangles there are part (a).