What i did is i set
, what's true for
. This itself is a linear function with a negative slope, but the function is always positive before
. It starts from B and does down linearly untill
. So theoretically the overall function increases untill
, after this point, the partial derivative gets negative (
) and henceforth starts from then on decreasing the overall function.
Is it correct that i thus say, the maximum of the function with three varibales is the same as the one with two, except for