Rock Throw
A rock is thrown directly up from a treehouse that is 20 feet above the ground. The height of the rock t seconds after it is thrown is modeled by the equation h=-16t^2+48t+20 where h is the height of the rock, in feet.
What does x represent?
time (seconds)
The function h(s)=-16s^2+40s+3 gives the height, in feet, of a tennis ball s seconds after someone hits the ball.
What does x represent?
time (seconds)
Assume the equation S=-3x^2+30x-3 models the sales of a recently released video game, where x is the number of weeks after release, and S is the number of weekly sales in millions.
What does x represent?
weeks after release
A video goes viral on social media, the number of views per day can be modeled with the equation y=-1.875x^2+22.5x where x is the number of days after the video is posted and y is the number of views per day in thousands.
What does x represent?
Number of days after video is posted
Solve by taking the square root:
(x + 1)2 + 1 = 50
6 and -8
A rock is thrown directly up from a treehouse that is 20 feet above the ground. The height of the rock t seconds after it is thrown is modeled by the equation h=-16t^2+48t+20 where h is the height of the rock, in feet.
What does y represent?
height (feet)
The function h(s)=-16s^2+40s+3 gives the height, in feet, of a tennis ball s seconds after someone hits the ball.
What does y represent?
height (feet)
Assume the equation S=-3x^2+30x-3 models the sales of a recently released video game, where x is the number of weeks after release, and S is the number of weekly sales in millions.
What does y represent?
number of weekly sales in millions
A video goes viral on social media, the number of views per day can be modeled with the equation y=-1.875x^2+22.5x where x is the number of days after the video is posted and y is the number of views per day in thousands.
What does y represent?
views per day in thousands
Solve by factoring:
2x2 - 26x + 80 = 0
2 (x-8)(x-5)
A rock is thrown directly up from a treehouse that is 20 feet above the ground. The height of the rock t seconds after it is thrown is modeled by the equation h=-16t^2+48t+20 where h is the height of the rock, in feet.
When will the rock reach it's maximum height?
1.5 seconds
The function h(s)=-16s^2+40s+3 gives the height, in feet, of a tennis ball s seconds after someone hits the ball.
What is the maximum height of the tennis ball?
28 feet
Assume the equation S=-3x^2+30x-3 models the sales of a recently released video game, where x is the number of weeks after release, and S is the number of weekly sales in millions.
According to this model, what are the peak weekly sales for the game?
$72 million
A video goes viral on social media, the number of views per day can be modeled with the equation y=-1.875x^2+22.5x where x is the number of days after the video is posted and y is the number of views per day in thousands.
On what day do the most people watch the video?
Day 6
Solve by completing the square:
x2 - 18x + 65 = 0
13, 5
A rock is thrown directly up from a treehouse that is 20 feet above the ground. The height of the rock t seconds after it is thrown is modeled by the equation h=-16t^2+48t+20 where h is the height of the rock, in feet.
What is the maximum height that the rock reaches?
56 feet
The function h(s)=-16s^2+40s+3 gives the height, in feet, of a tennis ball s seconds after someone hits the ball.
When does the tennis ball hit the ground?
2.57 seconds
Assume the equation S=-3x^2+30x-3 models the sales of a recently released video game, where x is the number of weeks after release, and S is the number of weekly sales in millions.
How many weeks after release until the peak weekly sales are reached?
5 weeks
A video goes viral on social media, the number of views per day can be modeled with the equation y=-1.875x^2+22.5x where x is the number of days after the video is posted and y is the number of views per day in thousands.
What is the maximum number of people that watch the video?
67.5 thousand people
Solve using the quadratic formula:
x2 +12x-24=0
-6 + 2 sq rt 15
-6 - 2 sq rt 15
A rock is thrown directly up from a treehouse that is 20 feet above the ground. The height of the rock t seconds after it is thrown is modeled by the equation h=-16t^2+48t+20 where h is the height of the rock, in feet.
What is the original height of the rock?
20 feet
The function h(s)=-16s^2+40s+3 gives the height, in feet, of a tennis ball s seconds after someone hits the ball.
How high off the ground is the ball 2 seconds into its flight?
19 feet
Assume the equation S=-3x^2+30x-3 models the sales of a recently released video game, where x is the number of weeks after release, and S is the number of weekly sales in millions.
When does the game stop selling?
9.9 weeks
A video goes viral on social media, the number of views per day can be modeled with the equation y=-1.875x^2+22.5x where x is the number of days after the video is posted and y is the number of views per day in thousands.
According to the model, after how many days do people stop watching the video?
12 days
Solve using any method:
x2 + 9x +14=0
-7, -2