9514 1404 393
Answer:
(-∞, -4] U [-1, ∞)
Step-by-step explanation:
The quadratic expression factors as ...
x^2 +5x +4 = (x +4)(x +1)
The zeros of this expression are where these factors are zero, at x=-4 and x=-1. The product is negative when one factor is negative and the other is positive, in the region -4 < x < -1. It is non-negative elsewhere. f(x) is defined where the quadratic is not negative, on the union of intervals ...
(-∞, -4] U [-1, ∞)
