Explanation:
for a function every valid x value must have exactly 1 y value. several x values can have the same y value assigned but never can a x value have multiple y values assigned.
the valid x values for m are -3. -2, -1, 1, 2, 3.
and indeed, every one of these values has exactly one y value out of the possible 1, 4, 9 values.
so, m is a function.
but the inverse function turns the meaning of x and y upside-down. x becomes y and y becomes x.
and now we see that for the inverse the x value of 1 has two assigned y values (-1, 1).
the same for 4 (-2, 2) and 9 (-3, 3).
so, the inverse is NOT a function.