document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=782127>Question 782127</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please help me answer this and give some explanations for easy understanding..<BR>\n" );
document.write( "Given:<BR>\n" );
document.write( "sin= -4/5  pi<theita<3pi/2<BR>\n" );
document.write( "Find sin2theita and sin theita/2\r<BR>\n" );
document.write( "\n" );
document.write( "Pls. reply as soon as possible  >_< </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #476294 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=476294\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Given:<BR>\n" );
document.write( "sin= -4/5 pi Find sin2theita and sin theita/2 <BR>\n" );
document.write( "----<BR>\n" );
document.write( "Assuming you mean sin(x) = -4/5 in QIII<BR>\n" );
document.write( "you would get cos(x) = -3/5<BR>\n" );
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document.write( "Then sin(2x) = 2*sin(x)cos(x) = 2(-4/5)(-3/5) = 24/25<BR>\n" );
document.write( "And sin(x/2) = sqrt[(1-(cos(x))/2] <BR>\n" );
document.write( "= sqrt[(1+(3/5))/2] = sqrt[4/5] = (2/5)sqrt(5)<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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