Domain and range of x^2+x-2/x^2-3x-4

For clarity, please enclose the denominator in parentheses:  (x^2-3x-4).

This is a rational function whose DOMAIN is "all real numbers for which the denominator is not zero."  Purposely set the denom. equal to zero and solve for x.  Answers:  {4,-1}.  Thus, the domain is "the set of all real numbers not equal to 4 or -1."  This can be written as (-infinity,-1) U (-1,4) U (4, infinity).

RANGE:  the set of all possible values of this rational function.  Please note that if we let x grow larger and larger, the value of this function approaches, but never equals, 1.  Thus, the RANGE is (-infinity, 1) U (1, infinity).