Question

Letf(x)=2x2 –5 and g(x)=x+4.

(a) Find the composite function ( f o g)(x) and simplify. Show work.
(b)Find (f og)(3).Showwork.

Answer 1

(fog) = f(g) = 2g^2-5 = 2(x+4)^2-5

now just expand that out

Now just plug in x=3 for (b).