The surface by the graph of the function z = f(x, y) with f(x, y) = sin(-x * y) + (y^2).

You are standing on the surface at point with coordinates(x0,y0)=(pi/4,1) and walking on the surface towards the point

(x1,y1)=(pi/2,1). Find the appropriate partial derivative and decide if on your way you will:

i) Go downhill

ii) Go uphill

iii) Go downhill parts of the way and uphill other parts.

As you go, does the slope become more steep or less steep?