a. The slew rate can be improved with higher closed-loop gain and dc supply voltage. But the slew rate also varies with temperature. i.e., slew rate decreases with increase in temperature. b. Another method for improving slew rate is, the rate at which voltage across the capacitor increases is gain by, dVc/dt = I / C. where, I is the maximum current furnished by the op-amp to the capacitor C. From the equation it is clear that for a higher slew rate, op-amp should have either a higher current or a small value of capacitor.