Question

Okay, I'm having some issues understanding my last homework assignment for the week...

Tickets=-0.2^2+12x+11
(x=1 is the day tickets go on sale)
does the graph of this equation open up or down?

Answer 1

oh my there should be a template made for this problem because there is at least one a day. where does it come from?!

Answer 2

it is a parabola that faces down because the "leading coefficient" is -.2 and that is negative

Answer 3

so it "opens down"

Answer 4

are you missing an X? should it be -0.2x^2?

Answer 5

to find the maximum number of tickets sold, and the day on which they are sold, use
\[-\frac{b}{2a}\] in this case
\[a=-.2,b=12\] so
\[-\frac{b}{2a}=\frac{12}{.4}=\frac{120}{4}=30\]

Answer 6

yeah I was missing an 'x' sorry I have sticky keys

Answer 7

it should open downward then :)

Answer 8

maximum tickets are sold on day 30. to find out how many tickets are sold, replace x by 30 and get
\[-.2\times 30^2+12\times 30+11=191\]

Answer 9

so on day 30 you sell 191 tickets and that is the maximum. it is also the vertex of the parabola. the vertex is (30,191)

Answer 10

there may be another question. like solve
\[-0.2x^2+12x+11 =0\] i forget. last day of ticket sales maybe?

Answer 11

after how many days will the peak/low occur... lol