What is the magnitude of the ideal transresistance transfer

Question

Consider given Problem

(a) What is the magnitude of the ideal transresistance transfer function |A_zf| as the transistor transconductance parameter g_m → ∞.

(b) Determine the value of g_m so that |A_zf | is within 95 percent of the ideal magnitude.

Problem

The transistor parameters for the circuit shown in Figure are V_TN = 0.4 V, K_n = 0.5 mA/V², and λ = 0.

(a) Find (i) the quiescent drain current I_DQ and (ii) the small-signal transistor parameters.

(b) Determine the transresistance transfer function A_{z f} = v_o/i_s.

(c) Find the output resistance R_of.