Consider the circuit shown in Fig. 4.50. (a) If Is1 = 21s2 = 3 x 10-16 A, determine Ve such that Ix = 0.90 mA. (b) What value of Rc places the transistors at the edge of the active mode? (a) VB = (b) Rc = V S2 H Rc Ix Q Q Figure 4.50 -Vcc=4.5V