SOLUTION: Looking at {{{f(x)=-0.2x^2+12x+11}}} After how many days will the peak or low occur?

Question 130299: Looking at

After how many days will the peak or low occur?
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
The peak corresponds to the vertex of the parabola. So let's find the x-coordinate of the vertex

In order to do that, we can use this formula:

From the equation we can see that a=-0.2 and b=12

Plug in b=12 and a=-0.2

Multiply 2 and -0.2 to get -0.4

Divide

So the x-coordinate of the vertex is

So at the x-coordinate of the vertex, the peak will occur. So on the 30th day, the peak in ticket sales will occur.