Explanation:
Start by finding (fog)(x)
To find this function, substitute x=
x−1
4
That is g(x) into f(x)
⇒(f∘g)(x)=(
x−1
4
)
2
−2(
x−1
4
)+5
=
(x−1)
2
16
−
x−1
8
+5
Now substitute x=3
⇒(f∘g)(3)=
(3−1)
2
16
−
3−1
8
+5
=
4
16
−
2
8
+5=4−4+5=5.
Hope it helps:)