申論題

3. In capital theory, one principle for the determining of the correct price of the firm's
capital is given by the equation:

where K (t) denotes the capital stock of some firm at time t, p (t) denotes the price per
unit of capital, R(t) denotes the rental price per unit of capital, and r is the constant
interest rate. That is, the current cost of capital should equal the discounted present
value of the returns from lending it.