The given function is
[tex]f(x)=x^2-5[/tex]
The right ordered pair must be consistent with this function, that is, if we enter an x-value then we should get the y-coordinate as result.
For example, let's evaluate the pair (2, -1). First, we replace x = 2 in the function.
[tex]f(2)=(2)^2-5=4-5=-1[/tex]
As you can observe, when we evaluate the function when x = 2, the function gave -1 as result, that means the pair (2, -1) belongs to this function.
Therefore, the right answer is b.
