document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1117289>Question 1117289</A>: <I><SPAN STYLE=\"word-break: break-all;\"> cos2x = -cosx for 0 &#8804; x < 2pi:  (Round to nearest tenth.) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #732378 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=732378\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> cos2x = -cosx<BR>\n" );
document.write( "----<BR>\n" );
document.write( "if you mean cos(2x) = -cos(x)<BR>\n" );
document.write( "2cos^2(x) - 1 = -cos(x)\r<BR>\n" );
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document.write( "2cos^2(x) + cos(x) - 1 = 0<BR>\n" );
document.write( "(2cos - 1)*(cos + 1) = 0<BR>\n" );
document.write( "cos(x) = -1<BR>\n" );
document.write( "x = pi<BR>\n" );
document.write( "=============<BR>\n" );
document.write( "2cos(x) - 1 = 0<BR>\n" );
document.write( "cos(x) = 1/2<BR>\n" );
document.write( "x = pi/3, 5pi/3  </SPAN>\n" );
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