Question

find domain when f(x)=-9/(x^2+4x)

Answer 1

set the denominator equal to 0 and solve for x


x^2+4x = 0

x = ?? or x = ??

Answer 2

what are you not seeing clearly

Answer 3

If the denominator of a fraction moves ever closer to zero as you move towards some value of x, then the result would be values of f(x) that will become ever larger as x gets closer to that value

Answer 4

for instance here , if x^2 + 4x can be zero at any x value, the function will go off to huge numbers as you get closer to that x value, and that x value is not defined or in the domain of the function