Question

Let f(x)=2x-1 and g(x)=x^2 -3. Find (f o g)(-3)

Answer 1

(f o g)(-3) = (f(g(-3))
Because g is on the inside, we carry out g first.

g(x) = x^2 - 3
Substitute -3 in for x.
g(-3) = (-3)^2 - 3 = 9 - 3 = 6
g(-3) = 6

Next, carry out f on the result of g(-3)
f(6) = 2(6) - 1
      = 12 - 1
      = 11
So the answer is 11.