Answer:


Step-by-step explanation:
The function  is incorrect as its roots are imaginary
 is incorrect as its roots are imaginary  .
.
So, the correct function is

Differentiating with respect to  we get
 we get

Equating with zero

Double derivative of the function

So, the function is maximum at 
Maximum profit is 

The maximum profit made by the company is 
The number of clients required to make the maximum profit is  .
.