Perform the inside functions first:
Then perform the outside functions on the results:
Now you can find the difference:
f(g(−3))−g(f(−3)) = 36−18 = 18
3 . D
The expression 7 − (4 − x)^2 will be at its maximum when the part after the
minus sign, (4 − x)^2 , is as small as it can be. Something squared can never
be less than zero, so the whole expression will be at its maximum when
(4 − x)^2 = 0:
4 . E