document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=169899>Question 169899</A>: <I><SPAN STYLE=\"word-break: break-all;\"> cos^2-sin^2=2cos^2-1 prove that this is true </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #125339 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=125339\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> cos^2-sin^2=2cos^2-1 prove that this is true<BR>\n" );
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document.write( "Note: sin^2(x) = 1 - cos^2(x)<BR>\n" );
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document.write( "Substitute that into the left side to get:\r<BR>\n" );
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document.write( "cos^2 -(1-cos^2) = 2cos^2-1<BR>\n" );
document.write( "cos^2 -1 + cos^2 = 2cos^2-1<BR>\n" );
document.write( "2cos^2 - 1 = 2cos^2 - 1<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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