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

3-106.

Examine the Riemann sum below for the area under .

How many rectangles were used?

Notice that the index starts at

and ends at . Also recall that

, where represents number of rectangles. If the area being approximated is

, what are and?is easy to spot in a Riemann sum. Now find the end-value,.

General form of a left-endpoint Riemann sum:You already computed how many rectangles there are part (a).

Notice that

, so each rectangle has a width of .