document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=839181>Question 839181</A>: <I><SPAN STYLE=\"word-break: break-all;\"> find cos x , if tan 2x=-3/4 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #505587 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=505587\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> find cos x , if tan 2x=-3/4<BR>\n" );
document.write( "***<BR>\n" );
document.write( "cos(2x)=-4/5<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%28x%29=cos%282x%2F2%29=sqrt%28%28cos%282x%29%2B1%29%2F2%29=sqrt%28%28%28-4%2F5%29%2B1%29%2F2%29=sqrt%28%281%2F5%29%2F2%29=sqrt%28%281%2F5%29%2F2%29=sqrt%281%2F10%29=sqrt%2810%29%2F10 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "\n" );
document.write( "calculator check:<BR>\n" );
document.write( "tan 2x=-3/4<BR>\n" );
document.write( "2x&#8776;143.13&#730;(in quadrant II in which tan<0)<BR>\n" );
document.write( "x&#8776;71.56&#730;<BR>\n" );
document.write( "..<BR>\n" );
document.write( "cosx as calculated=&#8730;10/10<BR>\n" );
document.write( "x&#8776;71.56&#730; </SPAN>\n" );
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