document.write( "Question 575890: A rain gutter is to be made of a sheet that is 10in wide by turning up the edges 90 degrees. \r
\n" ); document.write( "\n" ); document.write( "I have developed the formula for the cross sectional area by letting x define the unknown quantity of depth that is to be the independent value.
\n" ); document.write( "my formula is f(x)= 2x^2 + 10x\r
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\n" ); document.write( "\n" ); document.write( "My question is, what happens to the cross sectional area as depth size increases?
\n" ); document.write( "What x and y values make sense for this problem? (restricted domain and range)
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Algebra.Com's Answer #369690 by ankor@dixie-net.com(22740)\"\" \"About 
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A rain gutter is to be made of a sheet that is 10in wide by turning up the edges 90 degrees.
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\n" ); document.write( "Using the depth as x,
\n" ); document.write( "then
\n" ); document.write( "(10-2x) = the width of the gutter
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\n" ); document.write( "y = the cross sectional area
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\n" ); document.write( "y = depth * width
\n" ); document.write( "y = x(10-2x)
\n" ); document.write( "y = -2x^2 + 10x
\n" ); document.write( "or
\n" ); document.write( "f(x) = -2x^2 + 2x
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\n" ); document.write( "Graphing this would make it clear
\n" ); document.write( "\"+graph%28+300%2C+200%2C+-2%2C+8%2C+-10%2C+20%2C+-2x%5E2%2B10x%29+\"
\n" ); document.write( "You can see the domain is >0 to < 5, with max area when x= 2.5
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