document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1162379>Question 1162379</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Let cosA=-5/13 with A in Q3 and sinB=3/5 with B in Q1. Find sin(A-B), cos(A-B), and tan(A-B).\r<BR>\n" );
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document.write( "All I know how so far is just the formula sin(A-B)=sinAcosB-cosAsinB and cos(A-B)=cosAcosB+sinAsinB.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #786160 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13200)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><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=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=786160\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "5-12-13 and 3-4-5 are Pythagorean Triples.<br><BR>\n" );
document.write( "Given cosA = -5/12, sinA is 12/13 or -12/13, depending on the quadrant.<br><BR>\n" );
document.write( "Given sinB = 3/5, cosB is 4/5 or -4/5, depending on the quadrant.<br><BR>\n" );
document.write( "After you find sinA and cosB, use the formulas you show to find sin(A-B) and cos(A-B).<br><BR>\n" );
document.write( "Then tan(A-B) is just sin(A-B) divided by cos(A-B).<br><BR>\n" );
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