Answer:
To find when daily ticket sales peak, we need to find the maximum point of the quadratic equation N = -0.4x^2 + 9.6x + 10.
One way to do this is to use the formula for the x-coordinate of the vertex of a quadratic function, which is:
x = -b/2a
where a, b, and c are the coefficients of the quadratic equation ax^2 + bx + c. In this case, a = -0.4 and b = 9.6, so:
x = -9.6 / 2(-0.4) = 12
This means that daily ticket sales will peak 12 days after the concert was first announced.
To find how many tickets will be sold that day, we can substitute x = 12 into the equation for N:
N = -0.4x^2 + 9.6x + 10 = -0.4(12)^2 + 9.6(12) + 10 ≈ 51.2
Therefore, approximately 51 tickets will be sold on the day that daily ticket sales peak, 12 days after the concert was first announced.
Explanation: