z=arcsin(y^2/x)∂z/∂x = [1/√(1- (y^2/x)^2)] ( -y^2/x^2) = -(y^2/x) [1/√(x^2- y^4)]∂z/∂y = [1/√(1- (y^2/x)^2)] (2y/x) =2y/√(x^2- y^4)
