Find the output voltage of the following circuit assuming ideal op-amp behavior.

$$v\left(t\right)\;=5\left[\cos\left(10^6\mathrm{πt}\right)\;-\;\sin\left(10^3\mathrm{πt}\right)\times\sin\left(10^6\mathrm{πt}\right)\right]$$ represents

The bandwidth required for the transmission of a PCM signal increases by a factor of ________ when the number of quantization levels is increased from 4 to 64.

Tachometer feedback in a d.c. position control system enhances stability.