x = torch.tensor(2.0, requires_grad=True)
y = torch.tensor(3.0, requires_grad=True)

# Forward pass: compute z = x^2 + y^3
z = x**2 + y**3

# Backward pass: compute gradients
z.backward()
dz_dx = x.grad # partial derivative wrt x
dz_dy = y.grad # partial derivative wrt y