Question

The number if tickets sold each day for an upcoming performance of Handel's Messiah is given by N(x)=-0.6x^2+13.2x+12, where x is the number of days since the concert was first announced. When will daily ticket sales peak and tickets will be sold that day?

Ticket sales will peak ? days after the concert was first announced.

The number of tickets sold on that day will be ?

Answer 1

looks familiar. remember that to find the "vertex" of your parabola you use
\[-\frac{b}{2a}\] for the input

Answer 2

ur trying to find the maximum of the equation

Answer 3

in your case
\[a=-.6,b=13.2\]

Answer 4

Satellite I am having trouble still with the other I was confused which answer was which can you help me clarify please.

Answer 5

so your first job is to compute
\[-\frac{b}{2a}=-\frac{13.2}{2\times -.6}\]

Answer 6

no problem. is that much clear? you must compute
\[-\frac{b}{2a}\] first to get your answer

Answer 7

the "leading coefficient" of
\[-.6x^2+13.2+12\] is -.6 which is negative

so you know you will have a parabola which opens down

Answer 8

here is a nice picture of it
http://www.wolframalpha.com/input/?i=-.6x^2%2B13.2%2B12

Answer 9

the vertex is the highest point on the parabola. the first coordinate of the vertex will be
\[\frac{13.2}{1.2} \] by the formula \[-\frac{b}{2a}\]

Answer 10

\[\frac{13.2}{1.2}=11\] so the first coordinate of your vertex is 11

Answer 11

so what do i put in the answer then? 11

Answer 12

yes that is the first coordinate, correct

Answer 13

11days

Answer 14

eleven days. and to find out how many tickets are sold on that day, replace x by 11 and see what you get

Answer 15

in other words compute
\[-.6\times 11^2+13.2\times 11+12\]

Answer 16

i get 84.6 so i guess you have to round. now i have to run, but don't forget that formula for the vertex. first coordinate will be
\[-\frac{b}{2a}\]

Answer 17

so solve for n?

Answer 18

just replace x by 11 and you will get
\[N(11)=84.6\]

Answer 19

try it. good luck

Answer 20

right thx