A DAC uses a reference voltage of 80 V and has 6-bit precision. In four successive sampling

Question:

A DAC uses a reference voltage of 80 V and has 6-bit precision. In four successive sampling periods, each 1 second long, the binary data contained in the output register were 100000, 011111, 011101, and 011010. Determine the equation for the voltage as a function of time between sampling instants 3 and 4 using
(a) A zero-order hold, and
(b) A first-order hold.