Which graph shows a function whose inverse is also a function?

Hello!

If s(x) = x - 7 and t(x) = 4² - x + 3, find (t · s)(x) is also known as a composite function. (t · s)(x) is read as "t is composed of s", or "the composition of t and s".

(t · s)(x) = 4² -(x - 7) + 3

(t · s)(x) = 16 - x + 7 + 3

(t · s)(x) = -x + 16 + 7 + 3

(t · s)(x) = -x + 26

Therefore, (t · s)(x) = -x + 26.