document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=309287>Question 309287</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Prove each identity:\r<BR>\n" );
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document.write( "sin(x)sin(y)(cot(x)cot(y)-1)= cos(x+y)<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 #221226 by </B><A HREF=/tutors/aboutme.mpl?userid=Fombitz><B>Fombitz(32388)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Fombitz><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=Fombitz><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=221226\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sin%28x%29sin%28y%29%28cot%28x%29cot%28y%29-1%29=+sin%28x%29sin%28y%29%28%28cos%28x%29%2Fsin%28x%29%29%2A%28cos%28y%29%2Fsin%28y%29%29-1%29 ALIGN=MIDDLE   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=sin%28x%29sin%28y%29%28cot%28x%29cot%28y%29-1%29=cos%28x%2By%29 ALIGN=MIDDLE  ALT=\"sin%28x%29sin%28y%29%28cot%28x%29cot%28y%29-1%29=cos%28x%2By%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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