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March 14th, 2011, 08:31 AM   #1
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Find radius of circle if its area equals its circumferen

Q: Find the radius of a circle if its area is equal to its circumference.
It is damn difficult. Please help me solve this.
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March 14th, 2011, 08:42 AM   #2
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Re: Find radius of circle if its area equals its circumferen

I might reword this a little (not just the strong language!)...

"The area of a circle equals the circumference of (the same) circle"

Now "the area of a circle" is just

Somehow, this equals the circumference:

So

Pretty sure you can solve this!
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March 14th, 2011, 08:44 AM   #3
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Re: Find radius of circle if its area equals its circumferen

A=C
?*r*r=2*?*r
r=2
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March 17th, 2011, 07:28 AM   #4
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?rē = 2?r
? and r
? r = 2
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March 17th, 2011, 09:28 AM   #5
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Re: Find radius of circle if its area equals its circumferen

If we allow for the degenerate case, then r = 0 also works!
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March 18th, 2011, 09:36 AM   #6
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Re: Find radius of circle if its area equals its circumferen

Quote:
Originally Posted by MarkFL
If we allow for the degenerate case...!
...which we most certainly do... :@
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