### Home > APCALC > Chapter 2 > Lesson 2.2.2 > Problem2-70

2-70.

Alter your sigma notation from problem 2-69 to estimate the area with $16$ rectangles and use it to approximate the area. Were your results the same?

$\text{General form of left-endpoint rectangles: }\displaystyle \sum_{i=0}^{n-1}(\Delta x)(a + \Delta xi).$

$n$ represents number of rectangles.
$\Delta x$ represents width of each rectangle.
$a$ represents starting value on the $x$-axis.

$\text{Sigma notation from 2-69: }\displaystyle \sum_{i=0}^{7}(1)(-2+(1)(i)).$