Shoe Repair is C(q)=100+10q-q^2+(1/3)q^3, what is the firm’s marginal cost function? What is its profit-maximizing condition if the market price is p?…

If the cost function for John’s Shoe Repair is C(q)=100+10q-q^2+(1/3)q^3, what is the firm’s marginal cost function? What is its profit-maximizing condition if the market price is p? What is its supply curve?