document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1022170>Question 1022170</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Prove the following identities:<BR>\n" );
document.write( "A) cos2x/cosx+sinx = cosx - sinx<BR>\n" );
document.write( "B) 1-tan^2(x)/1+tan^2(x) = cos2x </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #637930 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=637930\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Prove the following identities:<BR>\n" );
document.write( "A) cos2x/cosx+sinx = cosx - sinx<BR>\n" );
document.write( "cos(2x) = cos^2(x) - sin^2(x)<BR>\n" );
document.write( "QED<BR>\n" );
document.write( "----------<BR>\n" );
document.write( "B) 1-tan^2(x)/1+tan^2(x) = cos2x<BR>\n" );
document.write( "(1-tan^2(x))*cos^2(x)/(1+tan^2(x))*cos^2(x)) = cos2x<BR>\n" );
document.write( "(cos^2(x) - sin^2(x)/(cos^2(x) + sin^2(x)) = cos(2x)<BR>\n" );
document.write( "cos^2(x) - sin^2(x) = cos(2x)<BR>\n" );
document.write( "QED<BR>\n" );
document.write( "====================<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );