Ok
so the focus is on the opening side of the parabola
so for a vertex of (h,k)
opening up and down
(x-h)²=4p(y-k)
p is the distance from vertex to focus
it is also the distance from the vertex to the closes point on directix
2p=distance from focus to directix
p is positive if the focus is above the directix
ok
y=9 and (7,6)
9>6
directix is above the vertex
p is negative
find distance
from 9 to 6 is 3
3=2p
1.5=p
p is negative
and the vertex will be 1.5 above the focus and 1.5 below the directix
vertex is (7,7.5)
(x-7)²=4(-1.5)(y-7.5) is de equation
<span>To find the average we need to sum the number of people in all the concert and divide it by the number of concert.
Average = (935+1100+1100) / 3
= 3135 / 3
Average number of people in the three concerts = 1045 people</span>
We know that the pool drains at a rate of 8 gallons per minute. We can multiply 8*11. 8*11 is 88. We can now subtract 88 from 143. This gives us 55. The swimming pool has 55 gallons of water after 11 minutes.
