The number of tickets sold each day for an upcoming performance of Handel,s Messiah is given by N(x)=-0.4^2+8.8x+10, where x is the number of days since the concert was first announced. When will daily ticket sales peak and how many tickets will be sold that day?

Answer 1

you know that ax^2+bx+c has its vertex at x = -b/2a.

Here, that means the vertex (maximum no. tickets) occurs at x = 11 days