document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=647516>Question 647516</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Refer to the graph of y = sin x or y = cos x to find the exact values of x in the interval [0, 4&#960;] that satisfy the equation. (Enter your answers as a comma-separated list.)<BR>\n" );
document.write( "3 cos x = 3/2 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #406281 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=406281\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Given<BR>\n" );
document.write( "(1) 3cos(x) = +3/2<BR>\n" );
document.write( "Dividing through by 3 we get<BR>\n" );
document.write( "(2) cos(x) = +1/2<BR>\n" );
document.write( "Using Invcos(.5) we get<BR>\n" );
document.write( "(3) x = + or - 60 degrees, or<BR>\n" );
document.write( "(4) x = 60, 300<BR>\n" );
document.write( "Adding 360 degrees to each yields the next pair of angles whose cosine is .5<BR>\n" );
document.write( "(5) x = 60 + 360 and 300 + 360 or<BR>\n" );
document.write( "(6) x = 420, 660<BR>\n" );
document.write( "Those angles that satisfy x = [0,720] are<BR>\n" );
document.write( "(7) x = {60, 300, 420, 660}<BR>\n" );
document.write( "The next angle whose cosine is .5 is 420+360 or 780, which is outside the domain of answers.<BR>\n" );
document.write( "Answer: x = {60,300,420,660} </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );