SOLUTION: the number of tickets sold each day for an upcoming performance is given by N9x) = -0.4x^2 + 9.6x + 12, where x is the number of days since the concert was first announced. When wi

Question 622269: the number of tickets sold each day for an upcoming performance is given by N9x) = -0.4x^2 + 9.6x + 12, where x is the number of days since the concert was first announced. When will daily tickets peak and how many tickets will be sold that day?
Answer by matineesuxxx(27) (Show Source): You can put this solution on YOUR website!
this question involves something called completing the square.
so first take your equation,
factor out the -0.4 from terms ax + bx and you will get,

now divide -24 by two and square it. you will get 144. add then subtract 144, as this wont change the equation.
now we have:

now multiply -0.4 by (-144) and move it outside the bracket so you get:

now the stuff inside the bracket is a perfect sqaure as
so now we have,

now since we are looking ffor the vertex, we have at 12 days, 70 tickets are sold.
NOTE: you can complete the square for any standard form quadratic, unlike factoring.
NOW if you know calculus this makes it much easier as all you need to do is take the derivative and set it to zero, as you will get

plug it into the initial equation, --->
RELATED QUESTIONS
The number of tickets sold each day for an upcoming performance of Handel's Messiah is... (answered by rwm)

The number of tickets sold each day for an upcoming performance of handel's messiah is... (answered by stanbon)

The number of tickets sold each day for an upcoming performance of handel's messiah is... (answered by stanbon,josmiceli)

The number of tickets sold each day for an upcoming performance of Handel's Messiah is... (answered by alicealc)

The number of tickets sold each day for an upcoming performance of Handel's Messiah is... (answered by aka042)

The number of tickets sold each day for an upcoming performance of Handel's Messiah is... (answered by ewatrrr)

9. Ticket Sales. The number of tickets sold each day for an upcoming performance of... (answered by josmiceli)

The number of tickets sold each day for an upcoming performance of Handel's Messiah given (answered by mananth)

The number of tickets sold each day for an upcoming performance of Handel's Messiah is... (answered by haileytucki)