I think you’re just reading the slide wrong. Take another careful look: on the RHS is it 3 x 2 times 2 x 1. On the LHS it is 3 x 1. That arrow goes from right to left, correct?
If you start the video at 2:20 of “Getting your matrix dimensions right”, you’ll see what I mean. It’s no big deal…thanks for your time
Even i faced the same issue. just check if u are reinitialzing paramtres in the code. meaning are u defining your own parameters and overwriting the one provided in function argument. (don’t type parameters=initialize(n_x,n_h,n_y)