Chain Rule for Vectors
Shapes: (k × m) · (m × n) = (k × n).
Why it matters: Backprop is this, applied right-to-left, never materializing full Jacobians — autograd stores each op’s vector-Jacobian product instead.
Shapes: (k × m) · (m × n) = (k × n).
Why it matters: Backprop is this, applied right-to-left, never materializing full Jacobians — autograd stores each op’s vector-Jacobian product instead.