document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=172974>Question 172974</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I have three questions that I need extreme help on.<BR>\n" );
document.write( "1.  Find sec thata if sin theta=-4/5 and 270 degrees<theta<360 degrees.<BR>\n" );
document.write( "2.  Simplify: (1/sec theta + sin^2 theta/cos theta)cos theta.<BR>\n" );
document.write( "3.  Find the exact value of: cos315 degrees.<BR>\n" );
document.write( "I have to show my work to get any credit.  Please help.<BR>\n" );
document.write( "Thanks </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #127821 by </B><A HREF=/tutors/aboutme.mpl?userid=midwood_trail><B>midwood_trail(310)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=midwood_trail><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=127821\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> I will do number 3 and leave the rest to others.\r<BR>\n" );
document.write( "\n" );
document.write( "3.  Find the exact value of: cos315 degrees.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Cos315 lies in quadrant 4.\r<BR>\n" );
document.write( "\n" );
document.write( "We need to find its reference angle.\r<BR>\n" );
document.write( "\n" );
document.write( "To do so, subtract 315 degrees from 360 degrees.\r<BR>\n" );
document.write( "\n" );
document.write( "Then:\r<BR>\n" );
document.write( "\n" );
document.write( "360 degrees - 315 degrees = 45 degrees\r<BR>\n" );
document.write( "\n" );
document.write( "The cosine of an angle is positive in quadrant 4.\r<BR>\n" );
document.write( "\n" );
document.write( "The exact value of cos315 = cos45 = sqrt{2}/2\r<BR>\n" );
document.write( "\n" );
document.write( "Final answer: sqrt{2}/2\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );