What is the inverse of the function? brainliest answer whoever answers it’s correct

First put a y in the place of f(x)
y = (1/3)^x
Then switch x and y
x = (1/3)^y
Solve for y
ln(x) = yln (1/3)
simplify
ln(x) = -ln(3)y
solve
y = -ln(x)/ln(3)

Aand b is what i think