document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1058160>Question 1058160</A>: <I><SPAN STYLE=\"word-break: break-all;\"> show that (cosa+sina)/(cosa-sina)-(cosa-sina)/(cosa+sina)=2tan2a </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #673184 by </B><A HREF=/tutors/aboutme.mpl?userid=solve_for_x><B>solve_for_x(190)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solve_for_x><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=673184\">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=%28cos+a+%2B+sin+a%29%2F%28cos+a+-+sin+a%29+-+%28cos+a+-+sin+a%29%2F%28cos+a+%2B+sin+a%29+=+2tan2a ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Multiplying each term to get a common denominator on the left side gives:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28%28cos+a+%2B+sin+a%29%2F%28cos+a+-+sin+a%29%29%28%28cos+a+%2B+sin+a%29%2F%28cos+a+%2B+sin+a%29%29+-+%28%28cos+a+-+sin+a%29%2F%28cos+a+%2B+sin+a%29%29%28%28cos+a+-+sin+a%29%2F%28cos+a+-+sin+a%29%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%28%28cosa%29%5E2+%2B+2%28sina%29%28cosa%29+%2B+%28sina%29%5E2+-+%28cosa%29%5E2+%2B+2%28sina%29%28cosa%29+-+%28sina%29%5E2%29%2F%28%28cosa%29%5E2+-+%28sina%29%5E2%29%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2%282%28sina%29%28cosa%29%29+%2F+%28%28cosa%29%5E2+-+%28sina%29%5E2%29%29 ALIGN=MIDDLE  ALT=\"+2%282%28sina%29%28cosa%29%29+%2F+%28%28cosa%29%5E2+-+%28sina%29%5E2%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Dividing both the numerator and the denominator by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28cosa%29%5E2 ALIGN=MIDDLE  ALT=\"%28cosa%29%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > gives:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2%2A2%28%28sina%29%2F%28cosa%29%29%2F+%281+-+%28sina%29%5E2%2F%28cosa%29%5E2%29 ALIGN=MIDDLE  ALT=\"+2%2A2%28%28sina%29%2F%28cosa%29%29%2F+%281+-+%28sina%29%5E2%2F%28cosa%29%5E2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2%282tana+%2F+%281+-+%28tana%29%5E2%29%29 ALIGN=MIDDLE  ALT=\"+2%282tana+%2F+%281+-+%28tana%29%5E2%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "But <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2tana%2F%281+-+%28tana%29%5E2%29+=+tan2a ALIGN=MIDDLE  ALT=\"2tana%2F%281+-+%28tana%29%5E2%29+=+tan2a\"   DISABLED_style= \"max-width:90%; height:auto;\" >, so\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2%282tana+%2F+%281+-+%28tana%29%5E2%29%29+=+2tan2a ALIGN=MIDDLE  ALT=\"+2%282tana+%2F+%281+-+%28tana%29%5E2%29%29+=+2tan2a\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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