You haven't included enough information for the question, but assuming that a and b are the same then a is 4 and b is 4
answer:

Step-by-step explanation:
On this question we see that we are given two points on a certain graph that has a maximum point at 57 feet and in 0.76 seconds after it is thrown, we know can say this point is a turning point of a graph of the rock that is thrown as we are told that the function f determines the rocks height above the road (in feet) in terms of the number of seconds t since the rock was thrown therefore this turning point coordinate can be written as (0.76, 57) as we are told the height represents y and x is represented by time in seconds. We are further given another point on the graph where the height is now 0 feet on the road then at this point its after 3.15 seconds in which the rock is thrown in therefore this coordinate is (3.15,0).
now we know if a rock is thrown it moves in a shape of a parabola which we see this equation is quadratic. Now we will use the turning point equation for a quadratic equation to get a equation for the height which the format is
, where (p,q) is the turning point. now we substitute the turning point
, now we will substitute the other point on the graph or on the function that we found which is (3.15, 0) then solve for a.
0 = a(3.15 - 0.76)^2 + 57
-57 =a(2.39)^2
-57 = a(5.7121)
-57/5.7121 =a
-9.9788169 = a then we substitute a to get the quadratic equation therefore f is

Answer:
Infinite solutions
Step-by-step explanation:
All solutions are possible.
Answer:
28.27 cm/s
Step-by-step explanation:
Though Process:
- The punch glass (call it bowl to have a shape in mind) is in the shape of a hemisphere
- the radius
- Punch is being poured into the bowl
- The height at which the punch is increasing in the bowl is

- the exposed area is a circle, (since the bowl is a hemisphere)
- the radius of this circle can be written as

- what is being asked is the rate of change of the exposed area when the height
- the rate of change of exposed area can be written as
. - since the exposed area is changing with respect to the height of punch. We can use the chain rule:

- and since
the chain rule above can simplified to
-- we can call this Eq(1)
Solution:
the area of the exposed circle is

the rate of change of this area can be, (using chain rule)
we can call this Eq(2)
what we are really concerned about is how
changes as the punch is being poured into the bowl i.e 
So we need another formula: Using the property of hemispheres and pythagoras theorem, we can use:

and rearrage the formula so that a is the subject:

now we can derivate a with respect to h to get 

simplify

we can put this in Eq(1) in place of 
and since we know 

and now we use substitute this
. in Eq(2)

simplify,

This is the rate of change of area, this is being asked in the quesiton!
Finally, we can put our known values:

from the question

