dz = dz/dx * dx + dz/dy * dydz/dx = ((x - y)^3 + x^(1/2) * sin y^2 + x * y)'_x == 3 * (x - y)^2 + 1/2 * x^(-1/2) * sin y^2 + ydz/dy = ((x - y)^3 + x^(1/2) * sin y^2 + x * y)'_y == -3 * (x - y)^2 + x^(1/2) * cos y^2 * 2y + xтогдаdz = (3 * (x - y)^2 + 1/2 * x^(-1/2) * sin y^2 + y) dx ++ (-3 * (x - y)^2 + 2 * x^(1/2) * y * cos y^2 + x) dy
