document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=956870>Question 956870</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Let tan theta = 5/12 with theta in QI Find Sec 2 theta -------- This chapter is on Double angle formulas. I do not know how to set up the equation for sec or csc.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #584612 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=584612\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let tan theta = 5/12 with theta in QI Find Sec 2 theta -------- This chapter is on Double angle formulas. I do not know how to set up the equation for sec or csc.<BR>\n" );
document.write( "***<BR>\n" );
document.write( "Working with a (5-12/13) reference right triangle in quadrant I<BR>\n" );
document.write( "tan theta=5/12=sin theta/cos theta<BR>\n" );
document.write( "cos theta=12/13<BR>\n" );
document.write( "sin theta=5/13<BR>\n" );
document.write( "cos 2 theta=cos^2 theta-sin^2 theta=144/169-25/169=119/169<BR>\n" );
document.write( "sec 2 theta=1/cos 2 theta<BR>\n" );
document.write( "sec 2 theta=169/119<BR>\n" );
document.write( "..<BR>\n" );
document.write( "Check w/calculator:<BR>\n" );
document.write( "tan theta=5/12<BR>\n" );
document.write( "theta&#8776;22.52<BR>\n" );
document.write( "2theta&#8776;45.24<BR>\n" );
document.write( "cos 2 theta=cos(45.24)&#8776;0.7041<BR>\n" );
document.write( "exact value=119/169&#8776;0.7041 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );