document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1058012>Question 1058012</A>: <I><SPAN STYLE=\"word-break: break-all;\"> sin(x+y)/cos(x+y) - sinx/cosx\r<BR>\n" );
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document.write( "how to simplify even sin(x+y) making cos alpha + beta formula </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #673046 by </B><A HREF=/tutors/aboutme.mpl?userid=solve_for_x><B>solve_for_x(190)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=solve_for_x><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=673046\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Multiply the first term by cos(x)/cos(x), and the second term by cos(x + y)/cos(x + y), which gives:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28sin%28x+%2B+y%29%2Fcos%28x+%2B+y%29%29%2A%28cos%28x%29%2Fcos%28x%29%29+-+%28sin%28x%29%2Fcos%28x%29%29%28cos%28x+%2B+y%29%2Fcos%28x+%2B+y%29%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=+%28sin%28x+%2B+y%29cos%28x%29+-+sin%28x%29cos%28x+%2B+y%29%29+%2F+cos%28x%29cos%28x+%2B+y%29+ ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Expanding sin(x + y) and cos(x + y) then gives:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%28%28sin%28x%29cos%28y%29%2Bcos%28x%29sin%28y%29%29cos%28x%29+-+sin%28x%29%28cos%28x%29cos%28y%29+-+sin%28x%29sin%28y%29%29%29+%2F+cos%28x%29cos%28x+%2B+y%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=+%28%28sin%28x%29cos%28y%29cos%28x%29+%2B+cos%5E2%28x%29sin%28y%29%29+-+sin%28x%29cos%28x%29cos%28y%29+%2B+sin%5E2%28x%29sin%28y%29%29+%2F+cos%28x%29cos%28x+%2B+y%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=+%28cos%5E2%28x%29sin%28y%29+%2B+sin%5E2%28x%29sin%28y%29%29+%2F+cos%28x%29cos%28x+%2B+y%29+ ALIGN=MIDDLE  ALT=\"+%28cos%5E2%28x%29sin%28y%29+%2B+sin%5E2%28x%29sin%28y%29%29+%2F+cos%28x%29cos%28x+%2B+y%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=+%28%28cos%5E2%28x%29+%2B+sin%5E2%28x%29%29sin%28y%29%29+%2F+cos%28x%29cos%28x+%2B+y%29+ ALIGN=MIDDLE  ALT=\"+%28%28cos%5E2%28x%29+%2B+sin%5E2%28x%29%29sin%28y%29%29+%2F+cos%28x%29cos%28x+%2B+y%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=+%28%281%29sin%28y%29%29+%2F+cos%28x%29cos%28x+%2B+y%29+ ALIGN=MIDDLE  ALT=\"+%28%281%29sin%28y%29%29+%2F+cos%28x%29cos%28x+%2B+y%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=+sin%28y%29+%2F+cos%28x%29cos%28x+%2B+y%29+ ALIGN=MIDDLE  ALT=\"+sin%28y%29+%2F+cos%28x%29cos%28x+%2B+y%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "If you want to go a step farther, the above expression is equivalent to:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+sec%28x%29sin%28y%29+%2F+cos%28x+%2B+y%29+ ALIGN=MIDDLE  ALT=\"+sec%28x%29sin%28y%29+%2F+cos%28x+%2B+y%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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