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#1 2010-10-19 01:40:17
- Laughsingrun
- Member
- Registered: 2010-10-05
- Posts: 5
Algebra
How would you find the diameter of a right cylinder if all you knew was it's height (12 in), surface area (219 in square), and surface area formula (2(pi)radius squared + 2(pi)radius x height)?
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#2 2010-10-19 01:56:09
- bobbym
- bumpkin
- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606
Re: Algebra
Hi Laughsingrun;
It is long and tedious but no different. Start like this.
Divide by pi.
Divide by 2.
Rearrange.
Now use the quadratic formula to solve for r. If you do not know how please read this.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.
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