Answer:
-1
Explanation:
y = f(x)
y = 6 * 3^x
Interchange x and y
x = 6 * 3^y
Divide by 6
x/6 = 3^y
Take the log of both sides
log(x/6) = log(3)^y
Bring the y down
log(x/6) = y log(3)
Divide by log(3)
log(x/6)/log(3) = y
Let x = 2
log(2/6) / log(3) = y
-(0.4771 )/ 0.4771 = y
y = - 1
Remark
The original graph is in green
The red graph is the inverse.
The point (2,-1) is marked so that you know it falls on the inverse.