SOLUTION: The equation is tickets= -0.2x^2+12x+11. what would be the last day tickets are sold? How many days would the peak occur?

Algebra.Com
Question 178883: The equation is tickets= -0.2x^2+12x+11.
what would be the last day tickets are sold? How many days would the peak occur?

Answer by nerdybill(7384)   (Show Source): You can put this solution on YOUR website!
The equation is tickets= -0.2x^2+12x+11.
.
By inspecting the coefficient associated with the x^2 term, we see that it is negative therefore the parabola is opens downward. If so, finding the vertex will tell us the maximum.
.
axis of symmetry = -b/2a
= -12/(2(-0.2))
= -12/(-0.4)
= 30 days (days would the peak occur)
.
Setting the equation to zero then solve for x:
0 = -0.2x^2+12x+11
Since we can't factor, solve using the quadratic equation. Doing so, yields:
x = {-0.9, 60.9}
Tossing out the negative solution the answer is:
61 days (number of days before tickets are sold)
.
Details of quadratic:
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation (in our case ) has the following solutons:



For these solutions to exist, the discriminant should not be a negative number.

First, we need to compute the discriminant : .

Discriminant d=152.8 is greater than zero. That means that there are two solutions: .




Quadratic expression can be factored:

Again, the answer is: -0.903074280724887, 60.9030742807249. Here's your graph:


RELATED QUESTIONS

Tickets = -0.2x^2+12x+11 a. does the graph of this equation open up or down? how did... (answered by solver91311)
I need help with the following quadratic equation: 1.Suppose you are an event... (answered by solver91311)
Suppose you are an event coordinator for a large performance theater. One of the hottest... (answered by mananth)
You are an event coordinator for a large performance theater. One of the hottest new... (answered by Edwin McCravy)
I'm trying to find the number of tickets sold on the last day, how many days will the... (answered by richard1234)
Suppose you are an event coordinatorfor a large performance theater. One of the... (answered by stanbon)
1) You provide the manager with a quadratic equation that models the expected number of (answered by ankor@dixie-net.com)
In the equation -0.2x^2+12x+11, would the graph open up or down? What would happen to... (answered by checkley77)
Tickets= -0.2x squared + 12x + 11 Does the graph open up or down and why. Describe what (answered by ankor@dixie-net.com)