A firm that maximizes the profit produced according to the production function f (x) = 4x^0.5. The price

selling output is $ 80, while the unit cost of input x is $ 40.

a) Find x, f (x) and the profit at equilibrium.

b) Without doing any calculations, say what will happen (rise or fall) to x, f (x) and to profit if the price of

sale increases.