Question

assuming I=50p^2=1000p, what would be a good charge for a weekly bus pass to maximize income sails ? (quadratic functions stuff)

Answer 1

Change the equation into standard form.
i = -50p^2 +1000p

Transform the equation into vertex form.
i = -50(p-20)^2

Now since the parabola opens down, you can find the maximum value by finding where the vertex lies on the graph. The vertex is (20,0).