document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=851835>Question 851835</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find sin theta if sec theta =-8/5 and tan theta <0 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #513010 by </B><A HREF=/tutors/aboutme.mpl?userid=Seutip><B>Seutip(231)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Seutip><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/cgi-bin/show-face.mpl?user=Seutip><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=513010\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Since tan and sec is negative therefore it is in quadrant 2, wherein only sin and csc are positive. :)\r<BR>\n" );
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document.write( "sec = -8/5 therefore,<BR>\n" );
document.write( "cos = -5/8 because cos is the reciprocal of sec,\r<BR>\n" );
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document.write( "It is stated in the Pythagorean identities that,<BR>\n" );
document.write( "cos^2+sin^2 =1\r<BR>\n" );
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document.write( "Therefore,<BR>\n" );
document.write( "sin^2 =1-cos^2\r<BR>\n" );
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document.write( "Substitute,\r<BR>\n" );
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document.write( "sin^2 =1-(-5/8)^2<BR>\n" );
document.write( "sin^2 =1-(25/64)<BR>\n" );
document.write( "sin^2 =(64/64)-(25/64)<BR>\n" );
document.write( "sqrt(sin^2) = sqrt(39/64)<BR>\n" );
document.write( "sin = sqrt39/8\r<BR>\n" );
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document.write( "That is the value of sin squareroot of 39 over 8, hope that helps! :) </SPAN>\n" );
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