# Tag Info

The problem was that $\frac{∂y'}{∂w_{111}} \neq \frac{∂z_{a1}}{∂w_{111}}$, but $\frac{∂y'}{∂w_{111}} = \frac{∂z_{b}}{∂w_{111}}$, where $z_b$ is the sum of the products of all the z-vectors of the last ...