I solved for K an L. and L doesn't depend on Q. what does this imply about the expansion path? explanation please.

7.20 Consider the production function O = K + VL. For this production function, MP, = 1/(2VL) and MPK = 1. Derive the input demand curves for L and K, as a function of the input prices w (price of labor services) and r (price of capital services). Show that at an interior optimum (with K > 0 and L > 0) the amount of L demanded does not depend on Q. What does this imply about the expansion path