### Home > CALC > Chapter 2 > Lesson 2.2.3 > Problem2-84

2-84.

Write a Riemann sum for a general function $f(x)$ to estimate $A(f, 2 ≤ x ≤ 5)$ using $n$ left endpoint rectangles of equal width if:

1. $n = 3$ rectangles

1. $n = 9$ rectangles

1. $n = 300$ rectangles

General form of left-endpoint Riemann Sum:

$n$ represents number of rectangles
$a$ represents starting value on the $x$-axis
$b$ represents ending value on the $x$-axis