Consider the acceleration due to gravity, g, at a height h above the surface of a planet of mass m.
(a) If m is held constant, is g an increasing or decreasing function of h? Why?
(b) if h is held constant, is g an increasing or decreasing function of m? Why?
(a) g = f(h,m)
I would guess h.
(b) same equation. I'd guess yes as well.
Both factors seem equally involved in making the function decreasing or increasing.
I don't know how to solve these without guessing, though.