document.write( "Question 887134: Please help.
\n" ); document.write( "Find all real numbers that are not in the domain of the following function. Then give the domain in set notation. f(x)=2x/x^2+x-72 \n" ); document.write( "

Algebra.Com's Answer #536397 by Theo(13342) $\"\"$ $\"About$

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your equation is f(x) = 2x / (x^2 + x - 72)
\n" ); document.write( "factor the denominator to get:
\n" ); document.write( "f(x) = 2x / ((x+9)*(x-8))
\n" ); document.write( "the domain is all real number except x = -9 and x = 8 because either one of those will make the denominator = 0 and that leads to an answer that is undefined.
\n" ); document.write( "in set notation, the domain would be described as x is an element of the real number set such that { x element of R | x <> -9, 8 }
\n" ); document.write( "R represents the real number set.
\n" ); document.write( "here's a tutorial on set notation that might be helpful.
\n" ); document.write( "they do a better job of explaining it than i do.
\n" ); document.write( "the important point here is that your domain can be all real number except -9 and 8.
\n" ); document.write( "http://www.purplemath.com/modules/setnotn.htm
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