document.write( "Question 962508: Hello friends. I have a problem here that I am hoping someone can help me with . A right cylinder has a volume of 2pi cubic inches . Find the can dimensions that require the least amount of aluminum to be used in the can construction? Thank you in advance !!! \n" ); document.write( "
Algebra.Com's Answer #588090 by hkwu(60)\"\" \"About 
You can put this solution on YOUR website!
The volume is described by
\n" ); document.write( "\"pi%2Ar%5E2%2Ah=2pi\"
\n" ); document.write( "so
\n" ); document.write( "\"h=%282pi%29%2F%28pi%2Ar%5E2%29=2%2Fr%5E2\"
\n" ); document.write( "The surface area is described by
\n" ); document.write( "\"SA=2pi%2Ah%2B2%2Api%2Ar\"
\n" ); document.write( "\"SA=2pi%2A%282%2Fr%5E2%29%2B2%2Api%2Ar\"
\n" ); document.write( "\"SA=%284pi%29%2Fr%2B2%2Api%2Ar%5E2\"
\n" ); document.write( "Taking the derivative, we get
\n" ); document.write( "\"d%2F%28dr%29%2ASA=-4pi%2Fr%5E2%2B4pi%2Ar\"
\n" ); document.write( "\"d%2F%28dr%29%2ASA=%28-4pi%2B4pi%2Ar%5E3%29%2Fr%5E2\"
\n" ); document.write( "which is equal to zero when
\n" ); document.write( "\"-4pi%2B4pi%2Ar%5E3=0\"
\n" ); document.write( "\"-1%2Br%5E3=0\"
\n" ); document.write( "\"r%5E3=1\"
\n" ); document.write( "\"r=1\"
\n" ); document.write( "If you do the first derivative test, you'll find that this is indeed a minimum value. Thus
\n" ); document.write( "\"h=2%2F1%5E2=2\"
\n" ); document.write( "so the optimal dimensions are 1in radius by 2in height.
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