How do you determine if a utility function is homothetic? I understand that definitions say that if the MRS depends only on the ratio of the two goods, then the utility function is homothetic. Yet I have trouble understanding how to actually apply this definition. So A is indifferent between bundles satisfying:
(Y/K)+ln(X/K)=2 where X, Y >0 and (X, Y are the goods)
is this utility function homothetic? if so, why?