document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1087806>Question 1087806</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Write the expression as the&#8203; sine, cosine, or tangent of a&#8203; double-angle. Then find the exact value of the expression.\r<BR>\n" );
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document.write( "cos^2 135 degrees - sin^2 135 degrees </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #702100 by </B><A HREF=/tutors/aboutme.mpl?userid=ikleyn><B>ikleyn(52790)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ikleyn><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=ikleyn><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=702100\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> .<BR>\n" );
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document.write( "cos^2(135°) - sin^2(135°) = cos(135°)*cos(135°) - sin(135°)*sin(135°) =  (apply the adding formula for cosine) = \r\n" );
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document.write( "= cos(135° + 135°) = cos(270°) = 0.\r\n" );
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document.write( "Solved.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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