document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=759397>Question 759397</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If sinA= -12/13, Q3, and cosB=4/5, Q1, calculate the exact value:<BR>\n" );
document.write( "a) sec (A-B)<BR>\n" );
document.write( "b) cot (A-B) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #462015 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=462015\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If sinA= -12/13, Q3, and cosB=4/5, Q1, calculate the exact value:<BR>\n" );
document.write( "a) sec (A-B)<BR>\n" );
document.write( "b) cot (A-B)<BR>\n" );
document.write( "***<BR>\n" );
document.write( "sinA=-12/13<BR>\n" );
document.write( "cosA=-5/13 (5-12-13 reference right triangle in Q3)<BR>\n" );
document.write( "tanA=sin/cos=12/5<BR>\n" );
document.write( "..<BR>\n" );
document.write( "cosB=4/5<BR>\n" );
document.write( "sinB=3/5 (3-4-5  reference right triangle in Q1)<BR>\n" );
document.write( "tanB=sin/cos=3/4<BR>\n" );
document.write( "..<BR>\n" );
document.write( "Identity:<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%28A-B%29=cosAcosB%2BsinAsinB=-5%2F13%2A4%2F5-12%2F13%2A3%2F5=-20%2F65-36%2F65=-56%2F65 ALIGN=MIDDLE  ALT=\"cos%28A-B%29=cosAcosB%2BsinAsinB=-5%2F13%2A4%2F5-12%2F13%2A3%2F5=-20%2F65-36%2F65=-56%2F65\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "a) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sec+%28A-B%29=1%2Fcos%28A-B%29=-65%2F56 ALIGN=MIDDLE  ALT=\"sec+%28A-B%29=1%2Fcos%28A-B%29=-65%2F56\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "..<BR>\n" );
document.write( "Identity:<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=tan%28A-B%29=%28tanA-tanB%29%2F%281%2BtanAtanB%29=%2812%2F5-3%2F4%29%2F%281%2B12%2F5%2A3%2F4%29%0D%0A=%2848%2F20-15%2F20%29%2F%281%2B36%2F20%29=%2848%2F20-15%2F20%29%2F%2856%2F20%29=33%2F56 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "b) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cot+%28A-B%29=1%2Ftan%28A-B%29=56%2F33 ALIGN=MIDDLE  ALT=\"cot+%28A-B%29=1%2Ftan%28A-B%29=56%2F33\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "computer check:<BR>\n" );
document.write( "sinA=-12/13<BR>\n" );
document.write( "A&#8776;67.38+180&#8776;247.38º<BR>\n" );
document.write( "cosB=4/5<BR>\n" );
document.write( "B&#8776;36.87º<BR>\n" );
document.write( "A-B&#8776;247.38-36.87&#8776;210.51º<BR>\n" );
document.write( "..<BR>\n" );
document.write( "cos(A-B)=cos(210.51º)&#8776;-0.8615<BR>\n" );
document.write( "exact value=-56/65&#8776;-0.8615<BR>\n" );
document.write( "..<BR>\n" );
document.write( "tan(A-B)=tan(210.51º)&#8776;0.5892<BR>\n" );
document.write( "exact value=33/56&#8776;0.5892<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );