If f(x,y)=x2+xy+y2=3f(x, y) = x^2 + xy + y^2 = 3f(x,y)=x2+xy+y2=3, what is dy/dxdy/dxdy/dx at (1,1)(1, 1)(1,1)?
−1-1−1
111
000
1/21/21/2