Economics + Calculus

In economics, especially economist that deals with the long run economic growth will deal with the production function like this:
$q(K,L) = 3ln(K) + 2(L),$ where K = Physical Capital and L = Human Capital. Economists observed that an expansion path for the economy can actually expressed in a function like this: $K =L^{2}.$

Maximize dq/dL along this expansion path.