Answer:

for minimum cost the intersection point should be calculated i-e

By using calculator

As x can't be negative so x=0.4828
It's the minimum value because as we decrease the operating cost further the capital value will increase so this is the minimum value.
Graphical solution:
The potential risk that the investors may face when this is made use is that the issuer may not be able to make profit when the bonds are considered to offer as a guaranteed return because they are honored by law and with that, this will cause the value of the bond to be lowered when exposed in the market in which the return will also be lower when return to the investors.
Answer:
Marginal cost is defined as the additional cost incurred in adding a unit of product or service.
Marginal benefit is defined as the additional satisfaction or utility that the individual receives from consuming the added unit of product or service.
In every endeavor, we weigh the benefit and cost of a certain product, course of action or service. We aim to get the most out of every product or decision. We are driven to reach maximum profit at a minimum cost. Thus, when the marginal cost is greater than the marginal benefit, people will do less of an activity because it is not profitable.
Explanation: