(g ∘ f )(x) = g(f(x)) so out the range of f(x), only 3 and 4 are in the domain of g(x). both points to 3 so range of (g ∘ f )(x) is {3} while its domain is {0,7}
Edit - thanks to gustanika who pointed out my mistake! I have mis-read the 5 to be 3.
(g ∘ f )(x) = g(f(x)) so out the range of f(x), only 4 and 5 are in the domain of g(x). both points to 3 so range of (g ∘ f )(x) is {3} while its domain is {3,7,8}
Edit of an edit - thanks to gustanika again who pointed out my mistake in my edit!
(g ∘ f )(x) = g(f(x)) so out the range of f(x), only 4 and 5 are in the domain of g(x). both points to 3 so range of (g ∘ f )(x) is {3} while its domain is {0,3,8}