document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1039980>Question 1039980</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Hi,\r<BR>\n" );
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document.write( "I would like to start off by saying thank you for answering my question.\r<BR>\n" );
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document.write( "The text book has asked to prove the identity :<BR>\n" );
document.write( "tan2theta = (2tantheta)/(1-tan^2theta)\r<BR>\n" );
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document.write( "Your help is so greatly appreciated. You have no idea </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #654757 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=654757\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  prove the identity :<BR>\n" );
document.write( "tan2theta = (2tantheta)/(1-tan^2theta) <BR>\n" );
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document.write( "tan(2t) = sin(2t)/cos(2t)<BR>\n" );
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document.write( "= 2sin(t)cos(t)/(cos^2(t)-sin^2(t))<BR>\n" );
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document.write( "Divide numerator and denominator by cos^2(t) to get::<BR>\n" );
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document.write( "= 2sin(t)/cos(t) / (1-tan^2(t))<BR>\n" );
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document.write( "= 2*tan(t)/(1-tan^2(t))<BR>\n" );
document.write( "QED<BR>\n" );
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document.write( "Note:: You could find this proof online using Google.<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "--------------- </SPAN>\n" );
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