document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=155191>Question 155191</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/032113186x/algebrahomeworkh>precalculus</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> Prove the identity. (must work with left side) \r<BR>\n" );
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document.write( "(1-2sin(x)^2)=(cos(x)^2)  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #114250 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=114250\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> (1-2sin(x)^2)=(cos(x)^2)<BR>\n" );
document.write( "sin^2(x) + cos^2(x) - 2sin^2(x) = cos^2(x)<BR>\n" );
document.write( "cos^2(x) - sin^2(x) = cos^2(x)<BR>\n" );
document.write( "-sin^2(x) = 0<BR>\n" );
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document.write( "The original problem is NOT an identity.<BR>\n" );
document.write( "It leads to a statement that is true only for certain values of \"x\".<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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