document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=934380>Question 934380</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the tan(alpha-beta), if sin alpha=-5/13, cos beta=15/17, 3pie/2<alpha<2pie, and 0<beta<pie/2. So far I have cos alpha=12/13, and sin beta=8/17. I got stuck on how to even start it! \r<BR>\n" );
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document.write( "Please help! It will be greatly appreciated! Thank you<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #567426 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=567426\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find the tan(alpha-beta), if sin alpha=-5/13, cos beta=15/17, 3pie/2<alpha<2pie, and 0<beta<pie/2. So far I have cos alpha=12/13, and sin beta=8/17.<BR>\n" );
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document.write( "reference angle a is in quadrant IV where sin<0, cos>0<BR>\n" );
document.write( "sina=-5/13<BR>\n" );
document.write( "cosa=12/13<BR>\n" );
document.write( "tana=sin/cos=-5/12<BR>\n" );
document.write( "..<BR>\n" );
document.write( "reference angle b is in quadrant I where sin>0, cos>0<BR>\n" );
document.write( "cosb=15/17<BR>\n" );
document.write( "sinb=8/17<BR>\n" );
document.write( "tanb=8/15<BR>\n" );
document.write( "..<BR>\n" );
document.write( "tan(a+b)=(tana+tanb)/(1-tana*tanb)<BR>\n" );
document.write( "=(-5/12+8/15)/1-(-5/12)*8/15<BR>\n" );
document.write( "=(-25/60+32/60)/(1+40/180)<BR>\n" );
document.write( "=(7/60)/1+(2/9)=7/60/11/9=63/660<BR>\n" );
document.write( "tan(a+b)=63/660 </SPAN>\n" );
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