document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=816297>Question 816297</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please Prove the following identities\r<BR>\n" );
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document.write( "1.) Tan (x/2) = tan (x)/sec (x) + 1\r<BR>\n" );
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document.write( "2.) sin(2x) - tan(x) = tan(x) cos (2x)<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 #491646 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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=491646\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Please Prove the following identities<BR>\n" );
document.write( "1.) Tan (x/2) = tan (x)/sec (x) + 1<BR>\n" );
document.write( "start with right side:<BR>\n" );
document.write( "tanx/(secx+1)=(sin/cos)/((1/cos)+1)=(sin/cos)/((1+cos)/cos)<BR>\n" );
document.write( "=<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sin%28x%29%2F%281%2Bcos%28x%29%29=tan%28x%2F2%29 ALIGN=MIDDLE  ALT=\"sin%28x%29%2F%281%2Bcos%28x%29%29=tan%28x%2F2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "verified: right side=left side<BR>\n" );
document.write( "..<BR>\n" );
document.write( "2.) sin(2x) - tan(x) = tan(x) cos (2x)<BR>\n" );
document.write( "start with right side:<BR>\n" );
document.write( "tanxcos2x=(sin/cos)(2cos^2-1)=2sincos-sin/cos=sin(2x)-tan(x)<BR>\n" );
document.write( "verified: right side=left side </SPAN>\n" );
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