Answer
Option C is correct.
(g o f)(4) = 196
Explanation
f(x) = 3x
g(x) = (x + 2)²
We are then told to find
(g o f)(4)
We need to first interprete what (g o f) means
(g o f) refers to writing g(x) with f(x) replacing x. That is, f(x) replaces all the x that the function given by g(x) has.
(g o f) = g[f(x)]
g(x) = (x + 2)²
g[f(x)] = [f(x) + 2]²
Recall that f(x) = 3x
g[f(x)] = [3x + 2]²
We can then go further now to obtain (g o f)(4)
(g o f)(x) = g[f(x)] = [3x + 2]²
(g o f)(4) = [3(4) + 2]²
= [12 + 2]²
= 14²
= 196
Hence, option C is correct.
(g o f)(4) = 196
Hope this Helps!!!