Determine the variation of the equivalent capacitance with time in seconds for an instant when C_1 = C_2. The equivalent capacitance of a circuit C_o is calculated through C_2 C_3, with all capacitances measured in F. Capacitances C_1 and C_2 have their values increased at a rate of 0.1 ext{ uF/s}. The variance C_3 decreases at a rate of 0.1 ext{ uF/s}.