Posted by Jack on .
The number of tickets soldeach day for an upcoming performance of Handiel Messiah is given by N(x)=0.4x^2+9.6x+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.

algebra 
bobpursley,
Treat the equation as a parabola, find its vertex. When? what is the axis of symettry?