document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=733648>Question 733648</A>: <I><SPAN STYLE=\"word-break: break-all;\"> prove this <BR>\n" );
document.write( "cosa /(1+sina) = seca (1- sina) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #448510 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=448510\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> prove this <BR>\n" );
document.write( "cosa /(1+sina) = seca (1- sina)<BR>\n" );
document.write( "start with right side:<BR>\n" );
document.write( "sec(1-sin)=(1/cos)(1-sin)<BR>\n" );
document.write( "=((1-sin)/cos)*((1+sin)/(1+sin))<BR>\n" );
document.write( "=(1-sin^2)/(cos(1+sin))<BR>\n" );
document.write( "=cos^2/cos(1+sin)<BR>\n" );
document.write( "=cos/(1+sin)<BR>\n" );
document.write( "verified: right side=left side </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );