### Home > APCALC > Chapter 3 > Lesson 3.1.1 > Problem 3-9

3-9.

Write an expression using sigma notation that represents the sum of the areas of the rectangles shown for the function below. Note, the rectangles have equal widths.

Questions to consider:

How many rectangles are there, ?

Are they left-endpoint, right-endpoint or midpoint rectangles?

Left-endpoint:

Right-endpoint:

Midpoint:

What is the width/base of each rectangle,

What is the function?

What is the starting value,

On what interval is the area being approximated?