Interpreting Quadratic Functions

The height of a water balloon that is launched into the air is given by h(t) = -5t² + 40t + 2. From what height was the balloon released?

• 2 meters

• 5 meters

• 40 meters

• 20 meters

If a toy rocket is launched vertically upward from ground level with an initial velocity of 128 feet per second, then its height h after t seconds is given by the equation

h(t) = -16t² +128t

When will the object reach its maximum height?

• 4 ft

• 0 seconds

• 0 ft

• 4 seconds

• None of the above

Fireworks are fired from the roof of a 100-foot building. The equation h = -16t² +84t + 100 models the height, h, of the fireworks at any given time, t. How high do the fireworks get?

• 2.625

• 6.25

• 100

• 200

• 210.25

A dolphin jumps from the water at at initial velocity of 16 feet per second. The equation h = -8t² + 16t models the dolphin's height at any given time, t. What is the maximum height the dolphin jumps?

• 1 foot

• 5 feet

• 7 feet

• 8 feet

• 12 feet

What is the vertex?

• (5,2)

• (2,5)

• (-2,5)

• (-5,2)

What is the standard form of a quadratic function?

• y=mx+b

• ax+by=c

• y=ax²+bx+c

• y=(x+a)(x-b)

Suppose a parabola has vertex (1,-4) and also passes through the point (2,-1). Write the equation of the parabola in vertex form.

• y = (x - 1)² - 4

• y = 3(x - 1)² + 4

• y = 3(x - 1)² - 4

• y = 3(x + 1)² - 4

Write the following quadratic expression in vertex form
f(x) = x² + 10x + 21

Using the following 2 points, write an equation of the parabola by finding a first. 

• y=2(x+3)²-1

• y=2(x-1)²-3

• y=0.5(x+3)²-1

• y=0.5(x-1)²-3

Write the equation for the parabola shown in the graph. Write your answer in vertex form.