Answer:
(a) F(x) < 0 over the intervals (-∞, -0.7) and (0.76, 2.5)
Step-by-step explanation:
Wherever the function crosses the x-axis, its sign changes. This lets us make a map of the signs of the function, and identify intervals where it is positive and negative.
<h3>Sign changes</h3>
The x-intercepts are said to be at x ∈ {-0.7, 0.76, 2.5}. These three crossing points divide the graph into four (4) intervals. The sign of the function is given as positive at x=0 and negative at x = 1.9. So, our sign map is ...
< -0.7 . . . . . negative
-0.7 to 0.76 . . . . . positive (2 at x=0, for example)
0.76 to 2.5 . . . . . negative (-5.7 at 1.9, for example)
> 2.5 . . . . . positive
Choosing from the descriptions, the one that matches is ...
F(x) < 0 over the intervals (-∞, -0.7) and (0.76, 2.5)
