The following is my analysis. [![enter image description here][1]][1] [1]: https://i.sstatic.net/NHN08.png $$- \frac{V_{out}} {R_D} = (V_{in1} - V_p) g_{m1} + \frac{V_{out2} -V_p} {r_{o1}}$$ $$\Rightarrow - V_{out2} (\frac{1} {r_{o1}} + \frac{1} {R_D}) = V_{in1} g_{m1} - V_p (g_{m1} + \frac{1} {r_{o1}})$$ $$\Rightarrow V_p = \frac{V_{in1} g_{m1} + V_{out2} (\frac{1} {r_{o1}} + \frac{1} {R_D})} {g_{m1} + \frac{1} {r_{o1}}}$$