I am working with derivatives of the natural log.

in the most recent example. it was to find the derivative of f(x) = x (ln x)^3

f'(x) = (1)(ln x)^3 + x d/dx (ln x)^3

d/dx (ln x)^3 is 3(ln x)^2*(1/x) which becomes [3 (ln x)^2]/x but then in the example it shows [3 (ln x)^2/x] just becomes 3 (ln x)^2. what happens to the x on the bottom?