Answer:
(a) Profit function P(x) = 0.02x^2+60x-80
(b) Average profit P(x)/x = P/x = 0.02x+60-80/x
Marginal profit dP/dx = 0.04x+60
Explanation:
Cost function: C(x) = -0.02x^2+40x+80
Price function: p(x) = 100
(a) The profit function P(x) = x*p(x)-C(x) can be expressed as:
![P=x*p-C\\P=x*100-(-0.02x^(2) +40x+80)\\P=0.02x^(2)+60x-80](https://img.qammunity.org/2020/formulas/mathematics/college/558py0b8gj5kkbgivx7nr0it2rdzsoupwf.png)
(b)Average profit function: P(x)/x
![P/x=(0.02x^(2)+60x-80)/x\\P/x = 0.02x+60-80/x](https://img.qammunity.org/2020/formulas/mathematics/college/emeyz93gb48f59xc29mdbazdveo1wg83co.png)
Marginal profit function: dP/dx
![P=0.02x^(2)+60x-80\\dP/dx=0.02*2*x+60+0\\dP/dx=0.04x+60](https://img.qammunity.org/2020/formulas/mathematics/college/w71sgiwv7t6wxoocw7lzt9fiy802qedix9.png)