document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=642030>Question 642030</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I'm having trouble solving this equation: sin2theta = cos36 degrees. I have tried to use the double angle formula for sin2theta and split it into 2sintheta times costheta and end up getting 2sintheta times costheta = cos36 degrees, but I don't know what to do from there to get it to become a single trig function so that I can solve for theta.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #403935 by </B><A HREF=/tutors/aboutme.mpl?userid=DrBeeee><B>DrBeeee(684)</B></A><img src=\"/images/stars/stars-11.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=DrBeeee><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=403935\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The trig ID you need to use is <BR>\n" );
document.write( "(1) cos(x) = sin(90-x)<BR>\n" );
document.write( "Then your <BR>\n" );
document.write( "(2) cos(36) = sin(90-36) or<BR>\n" );
document.write( "(3) cos(36) = sin(54)<BR>\n" );
document.write( "Now you have<BR>\n" );
document.write( "(4) sin(2*A) = sin(54) or<BR>\n" );
document.write( "(5) 2*A = 54 or<BR>\n" );
document.write( "(6) A = 27<BR>\n" );
document.write( "Answer: Theta is 27 degrees  </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );