document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=673022>Question 673022</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find all t in the interval [0, 2&#960;] satisfying (cos t)2 + 4 cos t + 3 = 0.\r<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #418759 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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=418759\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find all t in the interval [0, 2&#960;] satisfying (cos t)2 + 4 cos t + 3 = 0.<BR>\n" );
document.write( "cos ^2 t+4cos t+3=0<BR>\n" );
document.write( "(cos t+3)(cos t+1)=0<BR>\n" );
document.write( "cos t+3=0<BR>\n" );
document.write( "cos t=-3 (reject, (-1 &#8804; cos t &#8804;1)<BR>\n" );
document.write( "(cos t+1)=0<BR>\n" );
document.write( "cos t=-1<BR>\n" );
document.write( "t=&#960;<BR>\n" );
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