# Simpson question

1. Apr 22, 2007

### okevino

a bowling pin is 36cm long and is a solid of revolution.
the following are measurement of the circumference every 4cm.
from the top.

6.2 22 18.8 16.3 18.8 27 32.7 31.4 28.3

use simpson to appro the volum...

is this how to do this question?
(36/4)/3 [6.2 + 4(22) + 2(16.3) + .... + 28.3]
=1686.3

2. Apr 22, 2007

### Gib Z

This is the method you should do. Now the measurements along the circumference is y.

The volume of revolution between a and b, around the x axis of a function y is given by

$$\pi \int^b_a y^2 dx$$

So now use simpsons rule to approximate the integral, and multiply the result by pi.

3. Apr 22, 2007

### okevino

what do i do with the $$y^2$$

4. Apr 22, 2007

### Gib Z

Well you know what y is, you can work out y^2.

You would know how to apply simpsons rule on y, try it on y^2.

5. Apr 22, 2007

### okevino

cuz there's no answer to my questions..
so i just trying to learn how to do it...
thanks man.. i think i got it..

6. Apr 22, 2007

No problem.