4.76 Let the BJTs of Fig. P4.76 have $I_s = 0.1$ fA.
(a) Assuming $V_A = \infty$ and negligible base currents, specify suitable values for $R_1$ and $R_2$ so that $I_{C1} = 1.0$ mA and $I_{C2} = 0.2$ mA.
(b) If $R_1 = 1.0$ k$\Omega$ and $R_2 = 3.0$ k$\Omega$, find $I_{C1}$ and $I_{C2}$.
Hint: use iterations for both BJTs.