If a function is positive the y-value is greater than 0; it's above the y-axis.
Can you retry? (one of the answer choices you said are right.)
You are very welcome!
For each one, we check to see if any part of the interval is below the x-axis. If so, we do not check that one. For (-2, 0), we can tell that the whole function is negative, not positive. (An example is (-1, -1.475), where the y-coordinate is negative.) For (0, 4), by inspection, there is no part of the graph below the x-axis. For (4, ∞), we see that something like (5, y) is already way under the x axis, so this is not a choice.
For (-∞, -2), we can see that all of it is above the x-axis. So, this is an option. For (2, 2.5), this includes the interval at the topmost part of the second curve. This is above the x-axis, so this is a choice. Finally, for (-1.5, -1), this is the bottommost part of the first curve, which is below the x-axis. So, this does not work.
So, our final answers are (0, 4), (-∞, -2), and (2, 2.5). (2nd, 4th, and 5th choices.)