Answer:
The value is 2/3
Step-by-step explanation:
In order to find this, we first need to find the inverse of the equation (f^-1). To do this, switch f(x) and x and then solve for the new f(x).
f(x) = 4x + 1/3
x = 4f(x) + 1/3
x - 1/3 = 4f(x)
1/4x - 1/12 = f(x)
f^-1(x) = 1/4x - 1/12
Now that we have the inverse function, we simply need to plug in 3 for x and we get the value we are searching for.
f^-1(x) = 1/4(3) - 1/12
f^-1(x) = 3/4 - 1/12
f^-1(x) = 9/12 - 1/12
f^-1(x) = 8/12
f^-1(x) = 2/3