Need help in this question:

Suppose that you are the owner and operator of a perfectly competitive firm with the following total cost function:

TC = 1,000 + 5Q + 0.02Q2

Suppose further that the current market price is $25. By definition, TR = P x Q, so your total revenue function can be stated as:

TR = 25Q

i) Find the profit function

ii) Find the optimum quantity

iii) Find the profit