document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=204702>Question 204702</A>: <I><SPAN STYLE=\"word-break: break-all;\"> verify the trigonometric identity:<BR>\n" );
document.write( "(sinx-siny/cosx+cosy)+(cosx-cosy/sinx+siny)=0 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #154487 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=154487\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> verify the trigonometric identity:<BR>\n" );
document.write( "(sinx-siny/cosx+cosy)+(cosx-cosy/sinx+siny)=0<BR>\n" );
document.write( "--------------------<BR>\n" );
document.write( "Multiply thru by (cosx+cosy)(sinx+siny) to get:<BR>\n" );
document.write( "----<BR>\n" );
document.write( "(sinx-siny)(sinx+siny) + (cosx-cosy)(cosx+cosy) = 0<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Multiply to get:<BR>\n" );
document.write( "(sin^2x-sin^2y) + (cos^2x-cos^2y) = 0<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Substitute 1-sin^2 for each sin^2 to get:<BR>\n" );
document.write( "---<BR>\n" );
document.write( "sin^2x-sin^2y + 1-sin^2x -(1 - sin^2y) = 0<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Notice that the left side is zero.<BR>\n" );
document.write( "================================================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );