document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=943546>Question 943546</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the exact value of cos(2theta) given csctheta=5/2 and 0<theta<pi/2 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #575232 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=575232\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find the exact value of cos(2t) <BR>\n" );
document.write( "given csc(t) = 5/2 and 0 < t < pi/2<BR>\n" );
document.write( " ----<BR>\n" );
document.write( " csc = r/y, so r = 5 and y = 2<BR>\n" );
document.write( " Then x = sqrt[5^2-2^2] = sqrt(21)<BR>\n" );
document.write( " -----<BR>\n" );
document.write( " Therefore cos = x/r = sqrt(21)/5 and sin = 2/5<BR>\n" );
document.write( " ---------<BR>\n" );
document.write( " Ans: cos(2t) = cos^2 - sin^2 = (21/25)-(4/25) = 17/25<BR>\n" );
document.write( " ------------------<BR>\n" );
document.write( " Cheers,<BR>\n" );
document.write( " Stan H.<BR>\n" );
document.write( " ------------------ </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );