How do you find the domain for f(x) = (4x^2 - 9)/(x^2 + 5x + 6)?

1 Answer
George C.
Jun 7, 2015

To find the domain, we only need to factor the denominator to find its zeros. Other than the denominator being zero, f(x) is well defined for all x in RR.

x^2+5x+6 = (x+3)(x+2)

which is zero when x = -3 or x=-2

So the domain of f(x) is:

(-oo, -3) uu (-3, -2) uu (-2, oo)

That is {x in RR : x != -3 and x != -2}

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