document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=945993>Question 945993</A>: <I><SPAN STYLE=\"word-break: break-all;\"> cos(120) +cos(30) <BR>\n" );
document.write( "Using the product to sum formula  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #577070 by </B><A HREF=/tutors/aboutme.mpl?userid=MathLover1><B>MathLover1(20850)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=MathLover1><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=MathLover1><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=577070\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%28120%29+%2Bcos%2830%29+ ALIGN=MIDDLE  ALT=\"cos%28120%29+%2Bcos%2830%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( " you are supposed to express <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%28120%29 ALIGN=MIDDLE  ALT=\"cos%28120%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > as <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%2890+%2B+30%29 ALIGN=MIDDLE  ALT=\"cos%2890+%2B+30%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > and change it to single angles with the standard formula\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%28a+%2B+b%29+=+cos%28a%29%2Acos%28b%29+-+sin%28a%29%2Asin%28b%29 ALIGN=MIDDLE  ALT=\"cos%28a+%2B+b%29+=+cos%28a%29%2Acos%28b%29+-+sin%28a%29%2Asin%28b%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%2890%2B30%29+%2Bcos%2830%29 ALIGN=MIDDLE  ALT=\"cos%2890%2B30%29+%2Bcos%2830%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > \r<BR>\n" );
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document.write( "=<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%2890%29%2Acos%2830%29+-+sin%2890%29%2Asin%2830%29%2Bcos%2830%29 ALIGN=MIDDLE  ALT=\"cos%2890%29%2Acos%2830%29+-+sin%2890%29%2Asin%2830%29%2Bcos%2830%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > ........since <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%2890%29=0 ALIGN=MIDDLE  ALT=\"cos%2890%29=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sin%2890%29=1 ALIGN=MIDDLE  ALT=\"sin%2890%29=1\"   DISABLED_style= \"max-width:90%; height:auto;\" >, we have\r<BR>\n" );
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document.write( "=<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0%2Acos%2830%29+%2Bcos%2830%29+-+1%2Asin%2830%29 ALIGN=MIDDLE  ALT=\"0%2Acos%2830%29+%2Bcos%2830%29+-+1%2Asin%2830%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "=<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%2830%29+-+sin%2830%29 ALIGN=MIDDLE  ALT=\"cos%2830%29+-+sin%2830%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "=<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%283%29%2F2-1%2F2 ALIGN=MIDDLE  ALT=\"sqrt%283%29%2F2-1%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( " </SPAN>\n" );
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