document.write( "Question 706282: Hey guys, this question is related to applications of calculus (I couldn't find the section.
\n" ); document.write( "So, the question is as follows:\r
\n" ); document.write( "\n" ); document.write( "A rectangular block, the length of whose base is twice the width has a total surface area of 300cm^2. Find the dimensions of the block if it is of maximum volume. \r
\n" ); document.write( "\n" ); document.write( "Thank You
\n" ); document.write( "

Algebra.Com's Answer #435095 by josgarithmetic(39618)\"\" \"About 
You can put this solution on YOUR website!
x length, y width, z height.
\n" ); document.write( "volume of the box would be xyz.\r
\n" ); document.write( "\n" ); document.write( "x=2y as given, so volume is 2*y*y*z or volume \"v=2y%5E2z.\".\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Surface area was given as 300 cubic units. Accounting for the lengths measurements,
\n" ); document.write( "\"2%2A2%2Ay%2Ay%2B2yz%2B2%2Ay%2A2%2Az=300\"
\n" ); document.write( "4y^2+2yz+4yz=300
\n" ); document.write( "...and few more steps...
\n" ); document.write( "z=(300-4y^2)/(2y+4y)
\n" ); document.write( "\"z=%282%2F3%29%2875-y%5E2%29%2Fy\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Back to the volume formula,
\n" ); document.write( "\"v=2y%5E2%28z%29\"
\n" ); document.write( "v=2y^2(2/3)(75-y^2)/y
\n" ); document.write( "v=...
\n" ); document.write( "\"v=100y-%284%2F3%29y%5E3\" ----Taking derivative of formula in this form may be easiest.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The task to do now is the maximize v as a function of width y. Differentiate v with respect to y.
\n" ); document.write( "You then simply calculate x from knowing how x and y were given. Then you may need to use the z formula found above to caclulate z.
\n" ); document.write( "
\n" );