document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=813220>Question 813220</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If cos x = -1/5, find the value of cos(x+pi) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #489538 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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=489538\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If cos x = -1/5, find the value of cos(x+pi)<BR>\n" );
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document.write( "sinx=&#8730;(1-cos^2x)=&#8730;(1-1/25)=&#8730;(24/25)=&#8730;24/5<BR>\n" );
document.write( "Identity: cos(a+b)=cosa*cosb-sina*sinb<BR>\n" );
document.write( "..<BR>\n" );
document.write( "cos(x+&#960;)=cosx*cos&#960;-sinx*sin&#960;=(-1/5*-1)-(&#8730;24/5*0)=1/5 </SPAN>\n" );
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