# Thread: Approximate Integration

1. ## Approximate Integration

use simpson's rule with five function values to estimate the volume of the solid formed by rotating the curve y = 1/(1+x^2) about the X-axis between x = -2 and x=2.

I've never seen this sort of question before, combining both volumes and area under curve. Could someone please show me how it is done?

2. Just do it the same way except use washers.

$\displaystyle {\pi}\int_{-2}^{2}\left(\frac{1}{1+x^{2}}\right)^{2}dx$

By 5 function values, I reckon you mean 5 subintervals.

$\displaystyle \frac{b-a}{3n}=\frac{2-(-2)}{3(5)}=\frac{4}{15}$

3. ummm wat are washers?