I need help with this Trig Problem Asap

Answer:
Step-by-step explanation:
A function is one-to-one if it passes the horizontal line test. This is the case if a horizontal line intersects the graph in only one place.
The graph of f(x) = x^2 - 5 is that of a parabola that opens upward. There are several possibilities here:
1. The horizontal line intersects the parabolic graph twice on the interval (-infinity,+infinity). Therefore this function is not one-to-one on this interval
(-infinity,+infinity).
2. If we define the domain as [0,+infinity), a horizontal line will intersect this parabolic graph only once. Therefore this function is one-to-one on [0,+infinity).