document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=438731>Question 438731</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Addition or subtraction formula to find the exact value\r<BR>\n" );
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document.write( "tan(7pi/12) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #303314 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=303314\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Addition or subtraction formula to find the exact value <BR>\n" );
document.write( "tan(7pi/12)<BR>\n" );
document.write( "..<BR>\n" );
document.write( "Addition formula for tan:<BR>\n" );
document.write( "tan(x+y)=(tanx+tany)/(1-tanxtany)<BR>\n" );
document.write( "let x=3pi/12=pi/4<BR>\n" );
document.write( "let y=4pi/12=pi/3<BR>\n" );
document.write( "tan(7pi/12 is in Quadrant II, therefore, it is negative.<BR>\n" );
document.write( "tanx=tan pi/4=1<BR>\n" );
document.write( "tany=tan pi/3=sqrt(3)<BR>\n" );
document.write( "tan(7pi/12)=tan(pi/4+pi/3)=(1+sqrt(3))/(1-sqrt(3))<BR>\n" );
document.write( "(1+sqrt(3)(1+sqrt(3)/(1+sqrt(3)(1-sqrt(3)<BR>\n" );
document.write( "(1+2sqrt(3)+3)/1-3<BR>\n" );
document.write( "(4+2sqrt(3))/-2<BR>\n" );
document.write( "-(2+sqrt(3))<BR>\n" );
document.write( "ans:<BR>\n" );
document.write( "tan(7pi/12)=-(2+sqrt(3))\r<BR>\n" );
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document.write( "note: you could also use the half-angle formula for tan to solve, which might be easier. </SPAN>\n" );
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