document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=772825>Question 772825</A>: <I><SPAN STYLE=\"word-break: break-all;\"> verify the identity \r<BR>\n" );
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document.write( "cos (x + pi/2) = -sin x </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #471142 by </B><A HREF=/tutors/aboutme.mpl?userid=tommyt3rd><B>tommyt3rd(5050)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=tommyt3rd><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=tommyt3rd><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=471142\">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=cos+%28x+%2B+pi%2F2%29=cos%28x%29cos%28pi%2F2%29-sin%28x%29sin%28pi%2F2%29 ALIGN=MIDDLE  ALT=\"cos+%28x+%2B+pi%2F2%29=cos%28x%29cos%28pi%2F2%29-sin%28x%29sin%28pi%2F2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "then we can write\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%28x%29%2A0-sin%28x%29%2A1=-sin%28x%29 ALIGN=MIDDLE  ALT=\"cos%28x%29%2A0-sin%28x%29%2A1=-sin%28x%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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