document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=140847>Question 140847</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Verify the identity.\r<BR>\n" );
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document.write( "(cos(x) - cos(y))/(sin(x) + sin(y)) + (sin(x) - sin(y))/(cos(x) + cos(y)) = 0 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #102510 by </B><A HREF=/tutors/aboutme.mpl?userid=solver91311><B>solver91311(24713)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solver91311><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=solver91311><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=102510\">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=%28cos%28x%29+-+cos%28y%29%29%2F%28sin%28x%29+%2B+sin%28y%29%29+%2B+%28sin%28x%29+-+sin%28y%29%29%2F%28cos%28x%29+%2B+cos%28y%29%29+=+0 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "LCD is just the product of the denominators, so:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28%28%28cos%28x%29+-+cos%28y%29%29%28cos%28x%29%2Bcos%28y%29%29%29+%2B+%28%28sin%28x%29+-+sin%28y%29%29%28sin%28x%29%2Bsin%28y%29%29%29%29%2F%28%28sin%28x%29%2Bsin%28y%29%29%28cos%28x%29+%2B+cos%28y%29%29%29+=+0 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=%28cos%5E2%28x%29-cos%5E2%28y%29%2Bsin%5E2%28x%29-sin%5E2%28y%29%29%2F%28%28sin%28x%29%2Bsin%28y%29%29%28cos%28x%29+%2B+cos%28y%29%29%29=0 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" > (Difference of 2 squares)\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28cos%5E2%28x%29%2Bsin%5E2%28x%29-cos%5E2%28y%29-sin%5E2%28y%29%29%2F%28%28sin%28x%29%2Bsin%28y%29%29%28cos%28x%29+%2B+cos%28y%29%29%29=0 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=%28cos%5E2%28x%29%2Bsin%5E2%28x%29-%28cos%5E2%28y%29%2Bsin%5E2%28y%29%29%29%2F%28%28sin%28x%29%2Bsin%28y%29%29%28cos%28x%29+%2B+cos%28y%29%29%29=0 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=%281-1%29%2F%28%28sin%28x%29%2Bsin%28y%29%29%28cos%28x%29+%2B+cos%28y%29%29%29=0 ALIGN=MIDDLE  ALT=\"%281-1%29%2F%28%28sin%28x%29%2Bsin%28y%29%29%28cos%28x%29+%2B+cos%28y%29%29%29=0\"   DISABLED_style= \"max-width:90%; height:auto;\" > (because <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%5E2%28alpha%29%2Bsin%5E2%28alpha%29=1 ALIGN=MIDDLE  ALT=\"cos%5E2%28alpha%29%2Bsin%5E2%28alpha%29=1\"   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=0%2F%28%28sin%28x%29%2Bsin%28y%29%29%28cos%28x%29+%2B+cos%28y%29%29%29=0 ALIGN=MIDDLE  ALT=\"0%2F%28%28sin%28x%29%2Bsin%28y%29%29%28cos%28x%29+%2B+cos%28y%29%29%29=0\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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