document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=352690>Question 352690</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find all numbers fro which the rational expression is undefined.\r<BR>\n" );
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document.write( "(r^3-9r)/(r^2-9)  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #252089 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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=252089\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The expression is undefined when the denominator is equal to zero. So set the denominator equal to zero to get <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%5E2-9=0 ALIGN=MIDDLE  ALT=\"r%5E2-9=0\"   DISABLED_style= \"max-width:90%; height:auto;\" > and solve for 'r' to get <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r=3 ALIGN=MIDDLE  ALT=\"r=3\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r=-3 ALIGN=MIDDLE  ALT=\"r=-3\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "So the expression is undefined when <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r=3 ALIGN=MIDDLE  ALT=\"r=3\"   DISABLED_style= \"max-width:90%; height:auto;\" > or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r=-3 ALIGN=MIDDLE  ALT=\"r=-3\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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