document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=949212>Question 949212</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If cos A= 1/5, and angle A terminates in quadrant IV, find cos1/2 A </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #579719 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=579719\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If cos A= 1/5, and angle A terminates in quadrant IV, find cos1/2 A<BR>\n" );
document.write( "***<BR>\n" );
document.write( "half-angle formula:<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+cos%28x%2F2%29=sqrt%28%281%2Bcosx%29%2F2%29 ALIGN=MIDDLE  ALT=\"+cos%28x%2F2%29=sqrt%28%281%2Bcosx%29%2F2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+cos%28A%2F2%29=-sqrt%28%281%2B%281%2F5%29%29%2F2%29=-sqrt%28%286%2F5%29%2F2%29 ALIGN=MIDDLE  ALT=\"+cos%28A%2F2%29=-sqrt%28%281%2B%281%2F5%29%29%2F2%29=-sqrt%28%286%2F5%29%2F2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >=-&#8730;(6/10)=-&#8730;(3/5)<BR>\n" );
document.write( "check:<BR>\n" );
document.write( "cosA=1/5 (Q4)<BR>\n" );
document.write( "A&#8776;281.54&#730;<BR>\n" );
document.write( "A/2&#8776;140.77&#730;<BR>\n" );
document.write( "cos(A/2)=cos(140.77)&#8776;-0.7746<BR>\n" );
document.write( "exact value as computed=-&#8730;3/5&#8776;-0.7746 </SPAN>\n" );
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