document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=766937>Question 766937</A>: <I><SPAN STYLE=\"word-break: break-all;\"> use an appropriate identity to find the exact value of the expression\r<BR>\n" );
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document.write( "cos (5pi/12) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #467320 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=467320\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> use an appropriate identity to find the exact value of the expression <BR>\n" );
document.write( "cos (5pi/12)<BR>\n" );
document.write( "------------------<BR>\n" );
document.write( "5/12 = 1/6 + 1/4 = 10/24 = 5/12<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "cos(5pi/12) = cos[pi/6+pi/4] = cos(pi/6)cos(pi/4) - sin(pi/6)sin(pi/4)<BR>\n" );
document.write( "----<BR>\n" );
document.write( "= (sqrt(3)/2))(sqrt(2)/2) - (1/2)(sqrt(2)/2)<BR>\n" );
document.write( "----<BR>\n" );
document.write( "= (sqrt(6))/4 - (sqrt(2))/4<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "= [sqrt(6)-sqrt(2)]/4<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "=============== </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );