document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=928623>Question 928623</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Solve the given equation in the interval [0,2pi]. <BR>\n" );
document.write( "The answer must be written as a multiple of pi. Give exact answers. Do not use decimal numbers. The answer must be an integer or a fraction. <BR>\n" );
document.write( "2 (sin x)^2-5 cos x - 4 = 0.<BR>\n" );
document.write( "Help would be appreciated dearly.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #563763 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=563763\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 2 (sin x)^2-5 cos x - 4 = 0.<BR>\n" );
document.write( " ------<BR>\n" );
document.write( "2(1-cos^2)-5cos - 4 = 0<BR>\n" );
document.write( "-------<BR>\n" );
document.write( "2 - 2cos^2 - 5cos - 4 = 0<BR>\n" );
document.write( "-----<BR>\n" );
document.write( "2cos^2 + 5cos +2 = 0<BR>\n" );
document.write( "----<BR>\n" );
document.write( "Factor::<BR>\n" );
document.write( "(2cos+1)(cos+2) = 0<BR>\n" );
document.write( "---<BR>\n" );
document.write( "cos(x) = -1/2 or cos(x) = -2<BR>\n" );
document.write( "-------<BR>\n" );
document.write( "cos(x) = -2 implies x = (2/3)pi or (4/3)pi<BR>\n" );
document.write( "----<BR>\n" );
document.write( "cos(x) = -2 is extraneous<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" );