document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=807653>Question 807653</A>: <I><SPAN STYLE=\"word-break: break-all;\"> What is the exact value of tan 105 degrees? I did the work but find myself lost on what I was doing in showing the work. Here's what I got. <BR>\n" );
document.write( "tan(45+60)<BR>\n" );
document.write( "so then I used a sum difference formula<BR>\n" );
document.write( "=tan(45)tan(60)/(1-tan(45)tan60) The top I got radical 3 plus 1 and bottom is -radical 3 plus 1 I tried on the calculator but it gave me negative(-) radical 3 minus 1 divided by 2. What did I do wrong? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #486417 by </B><A HREF=/tutors/aboutme.mpl?userid=fcabanski><B>fcabanski(1391)</B></A><img src=\"/images/stars/stars-12.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=fcabanski><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=486417\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> tan(x+y) does not = tan(45)tan(60)/(1-tan(45)tan(60) <P><BR>\n" );
document.write( "The identity is tan(x+y) = (tan(x) + tan(y))/(1-tan(x)tan(y))<P><BR>\n" );
document.write( "You multiplied instead of added (in the numerator). </SPAN>\n" );
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