Given a total profit of p(x) = 1.4x-0.02x^2-20 let x represent a number of days and find profit achieved and when that profit is made
Did you want Maximum profit ?
find the vertex of your parabola
the x of the vertex is -b/(2a)
= -1.4/(2(-.02)) = 35 days
p(35) = 1.4(35) - .02(35)^2 - 20 = 4.5 whatever units