1. Consider a monopolist facing the following market demand function:
$$Q = 120 - 2P$$
where $Q$ denotes quantity demanded and $P$ denotes price.
The firm's total cost function is given by:
$$TC = 20Q + 100$$
Answer the following questions:
(a) Derive the marginal revenue (MR) function and the marginal cost (MC) function. \((5\%)\)