document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1198891>Question 1198891</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Let alpha be the arc such that: alpha belongs to ] pie over 2, pie[ and cos alpha= -12 over 13. Without using a calculator find sin alpha and tan alpha </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #832590 by </B><A HREF=/tutors/aboutme.mpl?userid=math_tutor2020><B>math_tutor2020(3817)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=math_tutor2020><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=832590\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <font color=black size=3><BR>\n" );
document.write( "Angle alpha is on the interval ]pi/2, pi[ which is equivalent to saying pi/2 < alpha < pi<BR>\n" );
document.write( "Each endpoint is excluded. \r<BR>\n" );
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document.write( "Because pi/2 < alpha < pi, this angle is in quadrant Q2, which is in the northwest corner.\r<BR>\n" );
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document.write( "In Q2 we have these facts:<BR>\n" );
document.write( "cosine is negative<BR>\n" );
document.write( "sine is positive<BR>\n" );
document.write( "tangent is negative\r<BR>\n" );
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document.write( "cos(alpha) = -12/13 = adjacent/hypotenuse<BR>\n" );
document.write( "adjacent = -12<BR>\n" );
document.write( "hypotenuse = 13\r<BR>\n" );
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document.write( "Use the pythagorean theorem to find the opposite side is 5 units long.\r<BR>\n" );
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document.write( "opposite = 5<BR>\n" );
document.write( "adjacent = -12<BR>\n" );
document.write( "hypotenuse = 13\r<BR>\n" );
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document.write( "Then,<BR>\n" );
document.write( "sin(alpha) = opposite/hypotenuse<BR>\n" );
document.write( "sin(alpha) = <font color=red>5/13</font><BR>\n" );
document.write( "and<BR>\n" );
document.write( "tan(alpha) = opposite/adjacent<BR>\n" );
document.write( "tan(alpha) = 5/(-12)<BR>\n" );
document.write( "tan(alpha) = <font color=red>-5/12</font>\r<BR>\n" );
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document.write( "Diagram:<BR>\n" );
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