The number of tickets sold each day for an upcoming performance of Handel's Messiah is given by N(x)=-0.4x^2+12x+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?

1 answer

N(x)=-.4( x^2 -30 x -25)
N(x)=-.4( x^2-30x+225-250)
N(x)=-.4( x-15)^2 +.4(250)
so the maximum is at x=15

You solve for N(15).

Also, I recommend you graph this on your graphing calc, to see if it is correct.