Forward pass (from Section 11.3.2):

**z**^[1] = [0.5, -0.45, 0.1]^T - **a**^[1] = ReLU(**z**^[1]) = [0.5, 0.0, 0.1]^T - *z*^[2] = 0.6 - *y_hat* = sigma(0.6) = 0.6457