(a) Design a first-order active low-pass filter with a cutoff frequency of 2 kHz and a gain of 40dB for implementation in a digital stethoscope. Sketch the circuit diagram and show all calculations for your design. [8 marks] (b) A triangular input voltage Vin (t) with the foillowing characteristics is applied to the input of a differentiator circuit which has resistor R= 5 kN and C= 0.2F. At i = 0, Vin (1) = 0V, at t = 2ms, Vin (1) = 4V, at t = 4ms, Vin (t) = 0V, at t = 6, %3D Vin (1) = 4V, and at t = 6ms, Vin (t) = OV. %3D (i) Sketch the circuit diagram and the input voltage waveform. [4 marks] (ii) Find the output voltage from the differentiator circuit and sketch the output voltage waveform. [8 marks}