Hi Keith,
We know h(x) = (68x)^2.
Also h(x) = (f@g)(x) and g(x)=68x.
So for the composite function f@g(x), we can replace g(x) by 68x,so we get
h(x)
= f(68x) = (68x)^2. (1)
since the question wants you to find f(x), we can simply replace 68x by x.
so from (1), we get
f(x) = x^2
2/4/2014

Ye Hong K.