document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=449671>Question 449671</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If sin x = -(4/5) and x is in quadrant IV, find cos (1/2) x </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #309390 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=309390\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If sin x = -(4/5) and x is in quadrant IV, find cos (1/2) x<BR>\n" );
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document.write( "We are working with a 3-4-5 right triangle in quadrant IV where sin is negative and cos is positive.<BR>\n" );
document.write( "Cos x=3/5<BR>\n" );
document.write( "Using the half-angle formula for cosine,<BR>\n" );
document.write( "cos x/2=sqrt((1+cos x)/2)<BR>\n" );
document.write( "            =sqrt((1+3/5)/2<BR>\n" );
document.write( "            =sqrt((8/5)/2<BR>\n" );
document.write( "cos x/2 =&#8730;.8 (ans) </SPAN>\n" );
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