document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1063885>Question 1063885</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Write the equation of the line tangent to go (x-4)^2 +y^2 = 25 at x = 9 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #678964 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39617)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><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=678964\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> One of the points on this circle is  (9,0), the only point on this circle for which x=0.  The circle has center at  (4,0), so this radius  (of length 5)  from center to x=9 on the circle is perpendicular to the desired tangent line at x=9, which means, this tangent line is vertical, having undefined slope.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "The line asked for in the question is  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=9 ALIGN=MIDDLE  ALT=\"x=9\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "No taking of derivative needed. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );