AVC=AC-AFC,the AVC curve is simply the vertical difference
between the AC and AFC curve,
AFC gets less, the gap between AVC andAC narrows.since all
marginal costs are variable ,the
same relationship holds between MC and AVC as it did between MC
and AC ,that is ,when MC is
less than AVC ,it must be falling, if MC is greater than AVC .it
must be rising,
so ,as with the AC curve ,the MC curve crosses the AVC curve at
its minimum point