document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=123559>Question 123559</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I am practicing finding the domain of an expression in interval notation. A particular problem has brought confusion\r<BR>\n" );
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document.write( "radical x(square)-7x-18/x-12\r<BR>\n" );
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document.write( "I know that the denomenator cannot be zero, otherwise it would be undefined. So would the answer be  [-9,2] U [2,infinity)  and x cannot =12     ? <BR>\n" );
document.write( "Am I on the right track with this?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #90634 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=90634\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> radical x(square)-7x-18/x-12<BR>\n" );
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document.write( "Comment: It is difficult to tell what your numerator is.<BR>\n" );
document.write( "Maybe it is sqrt(x^2-7x-18)<BR>\n" );
document.write( "If that is true, x^2-7x-18 must not be negative<BR>\n" );
document.write( "(x-9)(x+2) < 0<BR>\n" );
document.write( "Draw a number line; plot the points x=-2 and x=9<BR>\n" );
document.write( "Find which interval contains the solution set:<BR>\n" );
document.write( "If x=-3 you get (-3-9)(-3+2)< 0 which is false<BR>\n" );
document.write( "If x=0 you get (0-9)(0+2)< 0 which is true<BR>\n" );
document.write( "If x= 10 you get (10-9)(10+2)< 0 which is false<BR>\n" );
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document.write( "So, the domain cannot be 12 and it cannot be in the interval (-2,9)<BR>\n" );
document.write( "The domain is all Real Numbers except 12 or -2 < x < 9<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. <BR>\n" );
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