If f (x) = x2 and g (x) = x + 6, find g (f (0))

Substitute first 0 to x of the the first function, this gives f (0) = 0 ² which is equal to zero. Substitute the value of f (0) to the second function which gives g (0) = 0 + 6. Thus, the value of g (f (0)) = 6.