document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=819659>Question 819659</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I'm not really understanding using the Sum and Difference Formulas to find Exact values. Maybe I just need some more in depth explanation of how it works but I'm having a hard time  finding the exact value of expression of Tan(105)-tan(-15)/1+Tan(105)Tan(-15) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #493179 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=493179\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Ans:<BR>\n" );
document.write( "Since tan(A-B) = [tan(A)-tan(B)]/[1+tan(A)tan(B)]<BR>\n" );
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document.write( "the exact value of the expression  <BR>\n" );
document.write( "[Tan(105)-tan(-15)]/[1+Tan(105)Tan(-15)]<BR>\n" );
document.write( "is tan[105-(-15)]<BR>\n" );
document.write( "= tan[120)<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( "================\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );