MC Quadratic Applications

Formula to find x is

X= -b/2a, where x is the number of balls

• 500

• -500

• .05

• -.05

What is the total daily cost of all the tennis balls produced?

Hint: you are finding "C". You found x in the first problem, then sub into the formula in the problem to find C.

• 500

• 2300

• -2300

• 7700

Find x by formula

x = -b/2a

• 450

• 4500

• -450

• -4500

HINT:

1. Find x by formula x= -b/2a

2. sub back into the formula given in the problem to find h

• x = -2 sec and h = -2 ft

• x = 512 sec and h = -5531650 ft

• x = 2 sec and h = 2 ft

• x = 2 sec and h = 254 ft.

 $v\left(t\right)\ =\ -3t^2+73t+50$  

The value of Jennifer's stock portfolio is given by the function above, where v is the value of the portfolio in  dollars and t is time in months. When will the value of Jennifer's portfolio be at the maximum? How much will Jennifer have in her portfolio? 

HINT: 
1. Find x, which is the value for t to see when it will be max months x=-b/2a
2. Sub x, value for t, back into equation to find v (max money). 

• x = 12.17 months and v = 494.08 dollars

• x = -12.17 and v = -1282.74 dollars 

• x = 12.17 months and v = 1282.74 dollars 

• x = -12.17 months and v = 494.08 dollars 

A raft is dropped from a helicopter 256 feet in the air above the ocean.  Its approximate height, h, after t seconds is given by the function h(t) = -16t² + 256.  How many seconds did it take the raft to hit the water? 

• -4
• 2
• 4
• 8

If the graph shows price vs profit, what is the maximum profit? 

• 35
• 12,000
• 12,500
• 60

An object in launched directly upward at 64 feet per second (ft/s) from a platform 80 feet high. Its height is represented by the equation 
s(t) = –16t² + 64t + 80.
What will be the object's maximum height? 

• 2 ft
• 80 ft
• 144 ft
• 64 ft

If path of a projectile is modeled by: 
h(t) = -16t² + 20t +6, what is the height after 1 second? 

• 6 feet 
• 20 feet 
• 10 feet 
• 4 feet 

When I want to find the maximum or minimum height of an object, I should_____.

• Set the equation = 0 and solve.
• Use x = (-b/2a) as my answer.
• Substitute x = 0 into the equation.
• Find the y-coordinate for the vertex.