document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1131925>Question 1131925</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If A, B, C are angles of a triangle, prove that<BR>\n" );
document.write( "cosA + cosB + cosC = 4sin(A/2)sin(B/2)sin(C/2) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #748660 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=748660\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> As <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A ALIGN=MIDDLE  ALT=\"A\"   DISABLED_style= \"max-width:90%; height:auto;\" >,<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=B ALIGN=MIDDLE  ALT=\"B\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=C ALIGN=MIDDLE  ALT=\"C\"   DISABLED_style= \"max-width:90%; height:auto;\" > are angles of a triangle, we have <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A%2BB%2BC=180 ALIGN=MIDDLE  ALT=\"A%2BB%2BC=180\"   DISABLED_style= \"max-width:90%; height:auto;\" > \r<BR>\n" );
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document.write( "and \r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A%2BB=180-C ALIGN=MIDDLE  ALT=\"A%2BB=180-C\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( " or \r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28A%2BB%29%2F2=90-C%2F2 ALIGN=MIDDLE  ALT=\"%28A%2BB%29%2F2=90-C%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Hence \r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%28A%29%2Bcos%28B%29%2Bcos%28C%29 ALIGN=MIDDLE  ALT=\"cos%28A%29%2Bcos%28B%29%2Bcos%28C%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=2cos%28A%2BB%29%2F2%29%2Acos%28A-B%29%2F2%29+%2B1-2sin%5E2%28C%2F2%29-1 ALIGN=MIDDLE  ALT=\"2cos%28A%2BB%29%2F2%29%2Acos%28A-B%29%2F2%29+%2B1-2sin%5E2%28C%2F2%29-1\"   DISABLED_style= \"max-width:90%; height:auto;\" >.......since <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28A%2BB%29%2F2=90-C%2F2 ALIGN=MIDDLE  ALT=\"%28A%2BB%29%2F2=90-C%2F2\"   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=2cos%2890-C%2F2%29%2Acos%28%28A-B%29%2F2%29%2B1+-2sin%5E2%28C%2F2%29 ALIGN=MIDDLE  ALT=\"2cos%2890-C%2F2%29%2Acos%28%28A-B%29%2F2%29%2B1+-2sin%5E2%28C%2F2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >...since <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%2890-C%2F2%29=sin%28C%2F2%29 ALIGN=MIDDLE  ALT=\"cos%2890-C%2F2%29=sin%28C%2F2%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=2sin%28C%2F2%29%2Acos%28%28A-B%29%2F2%29%2B1+-2sin%5E2%28C%2F2%29 ALIGN=MIDDLE  ALT=\"2sin%28C%2F2%29%2Acos%28%28A-B%29%2F2%29%2B1+-2sin%5E2%28C%2F2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >......factor\r<BR>\n" );
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document.write( "=<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2sin%28C%2F2%29%28cos%28%28A-B%29%2F2%29-sin%28C%2F2%29%29%2B1 ALIGN=MIDDLE  ALT=\"2sin%28C%2F2%29%28cos%28%28A-B%29%2F2%29-sin%28C%2F2%29%29%2B1\"   DISABLED_style= \"max-width:90%; height:auto;\" > ........from <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sin%28%28A%2BB%29%2F2%29=sine%2890-C%2F2%29 ALIGN=MIDDLE  ALT=\"sin%28%28A%2BB%29%2F2%29=sine%2890-C%2F2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >=><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sine%28%28A%2BB%29%2F2%29=sin%28C%2F2%29 ALIGN=MIDDLE  ALT=\"sine%28%28A%2BB%29%2F2%29=sin%28C%2F2%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=2sin%28C%2F2%29%28cos%28%28A-B%29%2F2%29-sin%28%28A%2BB%29%2F2%29%29%2B1 ALIGN=MIDDLE  ALT=\"2sin%28C%2F2%29%28cos%28%28A-B%29%2F2%29-sin%28%28A%2BB%29%2F2%29%29%2B1\"   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=2sin%28C%2F2%29%282sin%28A%2F2%29%2Asin%28B%2F2%29%29%2B1 ALIGN=MIDDLE  ALT=\"2sin%28C%2F2%29%282sin%28A%2F2%29%2Asin%28B%2F2%29%29%2B1\"   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=1%2B4sin%28A%2F2%29%2Asin%28B%2F2%29sin%28C%2F2%29 ALIGN=MIDDLE  ALT=\"1%2B4sin%28A%2F2%29%2Asin%28B%2F2%29sin%28C%2F2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( " </SPAN>\n" );
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