document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=290184>Question 290184</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Can you help me solve this identity?<BR>\n" );
document.write( "cos^(4)[theta]-sin^(4)[theta]=1-2sin^(2)[theta]\r<BR>\n" );
document.write( "\n" );
document.write( "I just don't understand this and would appreciate the help! =] </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #209991 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=209991\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> cos^(4)[theta]-sin^(4)[theta]=1-2sin^(2)[theta] <BR>\n" );
document.write( "Factor the left side.<BR>\n" );
document.write( "Substitute for \"1\" on the right side:<BR>\n" );
document.write( "------<BR>\n" );
document.write( "(cos^2-sin^2)(cos^2+sin^2) = (cos^2 + sin^2) - 2sin^2<BR>\n" );
document.write( "----<BR>\n" );
document.write( "Since cos^2+sin^2 = 1 you get:<BR>\n" );
document.write( "(cos^2-sin^2)(1) = cos^2-sin^2<BR>\n" );
document.write( "cos^2-sin^2 = cos^2-sin^2<BR>\n" );
document.write( "===============================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( " </SPAN>\n" );
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