document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1169459>Question 1169459</A>: <I><SPAN STYLE=\"word-break: break-all;\"> cos(2tan^-1(2/1)) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #794239 by </B><A HREF=/tutors/aboutme.mpl?userid=MathLover1><B>MathLover1(20850)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=MathLover1><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/cgi-bin/show-face.mpl?user=MathLover1><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=794239\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%282tan%5E-1%282%2F1%29%29 ALIGN=MIDDLE  ALT=\"cos%282tan%5E-1%282%2F1%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Use the following identity :\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%282x%29=+%28-1%2B2+cos+%5E2%28x%29%29 ALIGN=MIDDLE  ALT=\"cos%282x%29=+%28-1%2B2+cos+%5E2%28x%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "since <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=tan%5E-1%282%2F1%29=tan%5E-1%282%29 ALIGN=MIDDLE  ALT=\"x=tan%5E-1%282%2F1%29=tan%5E-1%282%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, we have\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%282tan%5E-1%282%29%29=+%28-1%2B2cos+%5E2%28tan%5E-1%282%29%29%29 ALIGN=MIDDLE  ALT=\"cos%282tan%5E-1%282%29%29=+%28-1%2B2cos+%5E2%28tan%5E-1%282%29%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Use the following identity: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%28tan%5E-1%28x%29%29=%28sqrt%281%2Bx%5E2%29%2F%281%2Bx%5E2%29%29 ALIGN=MIDDLE  ALT=\"cos%28tan%5E-1%28x%29%29=%28sqrt%281%2Bx%5E2%29%2F%281%2Bx%5E2%29%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=cos%282tan%5E-1%282%2F1%29%29=+%28-1%2B2%28sqrt%281%2Bx%5E2%29%2F%281%2Bx%5E2%29%29%5E2%29 ALIGN=MIDDLE  ALT=\"cos%282tan%5E-1%282%2F1%29%29=+%28-1%2B2%28sqrt%281%2Bx%5E2%29%2F%281%2Bx%5E2%29%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=cos%282tan%5E-1%282%2F1%29%29=+%28-1%2B2%28sqrt%281%2B2%5E2%29%2F%281%2B2%5E2%29%29%5E2%29 ALIGN=MIDDLE  ALT=\"cos%282tan%5E-1%282%2F1%29%29=+%28-1%2B2%28sqrt%281%2B2%5E2%29%2F%281%2B2%5E2%29%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=cos%282tan%5E-1%282%2F1%29%29=+-1%2B2%28%281%2B4%29%2F%281%2B4%29%5E2%29 ALIGN=MIDDLE  ALT=\"cos%282tan%5E-1%282%2F1%29%29=+-1%2B2%28%281%2B4%29%2F%281%2B4%29%5E2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( " <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%282tan%5E-1%282%2F1%29%29=+-1%2B2%285%2F25%29 ALIGN=MIDDLE  ALT=\"cos%282tan%5E-1%282%2F1%29%29=+-1%2B2%285%2F25%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( " <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%282tan%5E-1%282%2F1%29%29=+-1%2B2%2F5+ ALIGN=MIDDLE  ALT=\"cos%282tan%5E-1%282%2F1%29%29=+-1%2B2%2F5+\"   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=cos%282tan%5E-1%282%2F1%29%29=+-3%2F5+ ALIGN=MIDDLE  ALT=\"cos%282tan%5E-1%282%2F1%29%29=+-3%2F5+\"   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=cos%282tan%5E-1%282%2F1%29%29=+-0.6+ ALIGN=MIDDLE  ALT=\"cos%282tan%5E-1%282%2F1%29%29=+-0.6+\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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