Calculating output resistance

[Mohammed Abrar]

I tried calculating the output resistance of both the cases but got both of them wrong.

For the left one:

Since it is a common source amplifier:
(1+gm*r0)rs+r0

gm= gm1
r0= (1/Gm3||ro3||ro1)
rs= ro2

Can anyone tell me where exactly am I going wrong

 

[Tahmid]

Note that M3 is diode-connected so that it's effectively a resistance. M1 is configured to be a common source amp, but M2 is configured to be a common gate amp.