Thread: Volume of an Ice Cream.

1. [Solved] Volume of an Ice Cream.

I'm just wondering where I've gone wrong. The correct answer to this question is ~6.38 but I end up with -47, which is not possible.

The question is to find the volume of the 'ice cream' shaped solid in the diagram below. My solution is also there. I think its the integral from 0 - pi/6 of Sin(phi) that's messing me up. I don't know why I end up with a negative number. .

Thanks Guys & Girls.

2. Originally Posted by Spimon
I'm just wondering where I've gone wrong. The correct answer to this question is ~6.38 but I end up with -47, which is not possible.

The question is to find the volume of the 'ice cream' shaped solid in the diagram below. My solution is also there. I think its the integral from 0 - pi/6 of Sin(phi) that's messing me up. I don't know why I end up with a negative number. .

Thanks Guys & Girls.
For one thing:

$\displaystyle \int_0^{\pi/6}\sin(\phi)~d\phi = 1-\cos(\pi/6)$

RonL

3. OOohhhh that helps! Thanks

4. Woooot!!! The problem was I was using P-Cos(Pi/6) in degrees more of my calculator.
When I put it in radians mode or use -Cos(30) in degrees, it works