I have problem with input resistance of emitter follower.

But first quick check:

If I'm correct, equation for input resistance will be:

\(R_{in} = R_B || R_{in'}\)

where:

\(R_B = R_2 || R_3\)

\(R_{in'} \approx h_{ie} + (h_{fe} + 1)R_5\)

Ok, that was quite easy. But the real problem I have with this:

Question is the same - what is equation for input resistance?

First problem is with two transistors. I'm not sure about this part of equation, but it's the best of what I've think of:

\(R_{in'} \approx h_{ie1} + (h_{fe1} + 1)(h_{ie2} + (h_{fe2} + 1)R_5\)

But I don't know how to write the rest of the equation.