document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=645341>Question 645341</A>: <I><SPAN STYLE=\"word-break: break-all;\"> HELLO\r<BR>\n" );
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document.write( "I am having troubles with the following:\r<BR>\n" );
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document.write( "if cos(theta) = -1/3 and theta is in quadrant 3. Evaluate sin2(theta)\r<BR>\n" );
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document.write( "I do not know where to start.\r<BR>\n" );
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document.write( "thank you much. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #405436 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=405436\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> if cos(theta) = -1/3 and theta is in quadrant 3. Evaluate sin2(theta)<BR>\n" );
document.write( "use x for theta\r<BR>\n" );
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document.write( "given cosx=-1/3=adj side/hypotenuse<BR>\n" );
document.write( "opp side =-&#8730;[(hypotenuse^2)-(adj side^2)]=-&#8730;(9-1)=-&#8730;8<BR>\n" );
document.write( "sinx=-&#8730;8/3<BR>\n" );
document.write( "sin(2x)=2sinxcosx=2*-&#8730;8/3*-1/3=2&#8730;8/9=4&#8730;2/9 </SPAN>\n" );
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