Real World Quadratic Equations

Real World Quadratic Equations

Multiple Choice

A ball is thrown into the air from the edge of a 48-foot-high cliff so that it eventually lands on the ground. The graph below shows the height, y, of the ball from the ground after x seconds. How many seconds does it take for the ball to hit the ground?

• 5.5

• 0

• 2.5

• cannot be determined

Domain is always time.

Time is always 0 or positive.

X-Values, smallest x-value is 0

Since the domain is always 0 or positive numbers, the domain is always the set of

WHOLE NUMBERS (0, 1, 2, 3, ...) because

integers (...-3, -2, -1, 0, 1, 2, 3, ...) include negative numbers

Multiple Choice

When Noami throws a ball from the edge of the cliff, she believes that set of integers would be an appropriate domain. Why isn't this correct?

• Because time cannot be negative.

• Because the height of the ball cannot be negative.

Multiple Choice

What is an appropriate domain for this graph that represents the height of a ball thrown from the edge of a cliff over time?

• $0\le x\le5.5$

• $0\le y\le146$

• $0\le y\le5.5$

• $0\le x\le146$