document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=849128>Question 849128</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the exact value using a sum or difference identity. cos(165°)<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #511544 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=511544\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find the exact value using a sum or difference identity. cos(165°)<BR>\n" );
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document.write( "cos(165) = -cos(15) = -cos(60-45) = -[cos(60)cos(45)+sin(60)sin(45)]<BR>\n" );
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document.write( "= -[(1/2)(sqrt(2)/2) + (sqrt(3)/2)(sqrt(2)/2)]<BR>\n" );
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document.write( "= -[(sqrt(2)/4) + sqrt(6)/4]<BR>\n" );
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document.write( "= -[sqrt(2)+sqrt(6)]/4<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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