document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=679329>Question 679329</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I need help with verifying this trig identity. The problem is sec^4x-tan^4x / sec^2+ tan^2x = sec^2x +tan^2x.\r<BR>\n" );
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document.write( "I'm having a really hard time with the left side,but on the right side I changed it to 1/ cos^2x + sin^2x/ cos^2x then to 1+sin^2x/ cos^2x. \r<BR>\n" );
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document.write( "Help! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #421943 by </B><A HREF=/tutors/aboutme.mpl?userid=solver91311><B>solver91311(24713)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solver91311><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=solver91311><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=421943\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font face=\"Times New Roman\" size=\"+2\">\r<BR>\n" );
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document.write( "A little challenging, but once you see the trick...\r<BR>\n" );
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document.write( "Working with the LHS only:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \ \sec^4x\ -\ \tan^4x\ =\ \frac{1}{\cos^4x}\ -\ \frac{\sin^4x}{\cos^4x}\ =\ \">\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \ \frac{1}{\cos^2x}\,\cdot\,\frac{1}{\cos^2x}\ -\ \frac{\sin^2x}{\cos^2x}\,\cdot\,\frac{\sin^2x}{\cos^2x} \ =\ \">\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \ \frac{1}{\cos^4x}\left(1\ -\ \left(\sin^2x\right)\left(\sin^2x\right)\right)\ =\ \">\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \ \frac{1}{\cos^4x}\left(1\ -\ \left(1\ -\ \cos^2x\right)\left(1\ -\ \cos^2x\right)\right)\ =\ \">\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \ \frac{1}{\cos^4x}\left(1\ -\ \left(1\ -\ 2cos^2x\ +\ \cos^4x\right)\right)\ =\ \">\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \ \frac{1}{\cos^4x}\left(2cos^2x\ -\ \cos^4x\right)\ =\ \">\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE \ \ \ \ \ \ \ \ \ \ \frac{2\ -\ \cos^2x}{\cos^2x}\ =\ \frac{2\ -\ \left(1\ -\ \sin^2x\right)}{\cos^2x}\ =\ \frac{1\ +\ \sin^2x}{\cos^2x}\">\r<BR>\n" );
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document.write( "which is the same as your right side.\r<BR>\n" );
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document.write( "John<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=\"/cgi-bin/rendertex.cgi?\LARGE e^{i\pi}\ +\ 1\ =\ 0\"><BR>\n" );
document.write( "<font face=\"Math1\" size=\"+2\">Egw to Beta kai to Sigma</font><BR>\n" );
document.write( "My calculator said it, I believe it, that settles it<BR>\n" );
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