document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=591078>Question 591078</A>: <I><SPAN STYLE=\"word-break: break-all;\"> How can I prove this identity? (1-cos^2theta)(1+cos^2theta)=2sin^2theta-sin^4theta?\r<BR>\n" );
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document.write( "I tried to do it, and this is what I've come up with so far, and am not sure if I am doing it correctly.\r<BR>\n" );
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document.write( "Working with the left side, I have the following:\r<BR>\n" );
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document.write( "sin^2theta(1+cos^2theta) = \r<BR>\n" );
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document.write( "sin^2theta+(sin^2theta*cos^2theta)\r<BR>\n" );
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document.write( "And then it stops.<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 #375482 by </B><A HREF=/tutors/aboutme.mpl?userid=scott8148><B>scott8148(6628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=scott8148><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=scott8148><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=375482\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> FOILing the left side ___ 1 - cos^4 = 2 sin^2 - sin^4\r<BR>\n" );
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document.write( "adding (sin^4 - 1) ___ sin^4 - cos^4 = 2 sin^2 - 1\r<BR>\n" );
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document.write( "factoring ___ (sin^2 + cos^2) (sin^2 - cos^2) = 2 sin^2 - (sin^2 + cos^2)\r<BR>\n" );
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document.write( "1 (sin^2 - cos^2) = sin^2 - cos^2\r<BR>\n" );
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document.write( "1 = 1\r<BR>\n" );
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