Z’x = 4·y^2/2√(xy^2-2)=2y^2/√(xy^2-2)
Z’y=4·2xy/2√(xy^2-2)=4xy/√(xy^2-2)
dz=(2y^2/√(xy^2-2) )dx+(4xy/√(xy^2-2) )dy
Z’x = 4·y^2/2√(xy^2-2)=2y^2/√(xy^2-2)
Z’y=4·2xy/2√(xy^2-2)=4xy/√(xy^2-2)
dz=(2y^2/√(xy^2-2) )dx+(4xy/√(xy^2-2) )dy