document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1027528>Question 1027528</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Could you assist me in solving a problem please? I can solve every problem in Chapter 2 of my daughter’s college algebra book except one and its bothering me. The surface area \"S\" of a right circular cylinder is given by the formula \"S\" = 2&#960;rh + 2&#960;r^2. If the height is twice the radius, find each of the following: a) A function S(r) for the surface area as a function of r. b) A function S(h) for the surface area as a function of h. That's it. When I solve for h in the original equation its equal to -r in order to plug it back into the Volume formula to solve for V(r). How can h be equal to -r and 2r as suggested in the word problem? I am missing something and I simply don't know what it is. Thank you. <BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #642740 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39620)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=642740\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=system%28S=2%2Api%2Arh%2B2%2Api%2Ar%5E2%2Ch=2r%29 ALIGN=MIDDLE  ALT=\"system%28S=2%2Api%2Arh%2B2%2Api%2Ar%5E2%2Ch=2r%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "THE SECOND EQUATION IS IN THE PROBLEM DESCRIPTION!!\r<BR>\n" );
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document.write( "(a) Find the function S(r), surface area as a function or r.<BR>\n" );
document.write( "SUBSTITUTE FOR h ACCORDING TO THE PROBLEM DESCRIPTION:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=S%28r%29=2%2Api%2Ar%282r%29%2B2%2Api%2Ar%5E2 ALIGN=MIDDLE  ALT=\"S%28r%29=2%2Api%2Ar%282r%29%2B2%2Api%2Ar%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > through substitution;<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=S%28r%29=2%2A2%2Api%2Ar%2Ar%5E2%2B2%2Api%2Ar%5E2 ALIGN=MIDDLE  ALT=\"S%28r%29=2%2A2%2Api%2Ar%2Ar%5E2%2B2%2Api%2Ar%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28S%28r%29=4%2Api%2Ar%5E3%2B2%2Api%2Ar%5E2%29 ALIGN=MIDDLE  ALT=\"highlight%28S%28r%29=4%2Api%2Ar%5E3%2B2%2Api%2Ar%5E2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "(b) Find surface area as a function of cylinder height, h.<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=h=2r ALIGN=MIDDLE  ALT=\"h=2r\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=h%2F2=2r%2F2 ALIGN=MIDDLE  ALT=\"h%2F2=2r%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=h%2F2=r ALIGN=MIDDLE  ALT=\"h%2F2=r\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-<BR>\n" );
document.write( "Substitute for h in S.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=S%28h%29=2%2Api%28h%2F2%29%2Ah%2B2%2Api%2A%28h%2F2%29%5E2 ALIGN=MIDDLE  ALT=\"S%28h%29=2%2Api%28h%2F2%29%2Ah%2B2%2Api%2A%28h%2F2%29%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=S%28h%29=2%2Api%2Ah%2Ah%2F2%2B2%2Api%2Ah%5E2%2F%282%2A2%29 ALIGN=MIDDLE  ALT=\"S%28h%29=2%2Api%2Ah%2Ah%2F2%2B2%2Api%2Ah%5E2%2F%282%2A2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28S%28h%29=pi%2Ah%5E2%2B%28pi%2Ah%5E2%29%2F2%29 ALIGN=MIDDLE  ALT=\"highlight%28S%28h%29=pi%2Ah%5E2%2B%28pi%2Ah%5E2%29%2F2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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