Challenger Deep in the Mariana Trench is the deepest point in earth's ocean, at about 11 km below the surface. What is the gage pressure at that depth? Take the density of sea water to be 1035 kg/m2. Find an expression for the gradient of the pressure field, P(x, y) = y sin x + en 1: y2 cos x + 2y sin x O 2:2y sin x O 3: y2 cos xi + 2y sin xj 4:sin x + y 5: None of the above