Answer:
b. y ≤ 0
Explanation:
Do you mean f(x) = -x^2?
If so, think of f(x) = x^2. You can use any real number for x. Once you square each value of x, you can get zero or a positive real for y. f(x) can only be a non-negative number. Now look at your function: f(x) = -x^2. The values of y are the opposite of the values of y in f(x) = x^2, so the range of f(x) = -x^2 is zero and all negative reals.
Answer: b. y ≤ 0