document.write( "Question 29867: Determine the domain of the function h(x) = 3x/ x(x^2-81).\r
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Algebra.Com's Answer #16643 by sdmmadam@yahoo.com(530)\"\" \"About 
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h(x) = 3x/ x(x^2-81).
\n" ); document.write( "That is h(x) = 3/(x^2-81) (canceling x not zero)
\n" ); document.write( "Since division by zero is not defined, h(x) cannot be defined for (x^2-81)=0
\n" ); document.write( "And (x^2-81) = 0
\n" ); document.write( "implies (x+9)(x-9) = 0 (using a^2-b^2 = (a+b)(a-b) where a = x and b = 9)
\n" ); document.write( "that is for (x+9)=0 giving x=-9 and for (x-9) = 0 giving x = 9
\n" ); document.write( "Therefore the funciton h(x) is defined for all x EXCEPTING x = 9 and x = -9
\n" ); document.write( "Therefore the domain of the given function is the complement of {-9,9} in the real number system R
\n" ); document.write( "That is Domain = R - {-9,9}
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