document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=64455>Question 64455</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Hi. I'm not sure how to find the answer of this kind of equation:<BR>\n" );
document.write( "2cos(3x)+1=0. now, i can get as far as cos(3x)= -.5 and replace the 3x with an \"a\" and divide. I now get 3x=2pi/3 and 4pi/3. my problem is that i have to solve over a (0, 2pi] domain, and i'm not sure how to alter the domain once i divide my answers by 3. please help! thanks. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #45080 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=45080\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 2cos(3x)+1=0<BR>\n" );
document.write( "cos(3x)=-1/2<BR>\n" );
document.write( "Take the arccos of both sides to get:<BR>\n" );
document.write( "3x=120 degrees or (2/3)pi radians<BR>\n" );
document.write( "x=40 degrees or (2/9)pi radians<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );