Rock Throw
A rock is thrown directly up from a treehouse: h=-16t^2+48t+20. h=height.
What does t represent?
time (seconds)
A tennis ball is hit: h(s)=-16s^2+40s+3
What does s 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
Write the equation for:
(-4,0)
(-2,0)
(-3,-1)
y=x^2+6x+8
A rock is thrown directly up from a treehouse: h=-16t^2+48t+20
What does h 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 h(s) 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
Write the equation for:
(-3,0)
(3,0)
(0,-9)
y = x^2 - 9
A rock is thrown directly up from a treehouse: h=-16t^2+48t+20.
When will the rock reach it's maximum height?
1.5 seconds
A tennis ball is hit: h(s)=-16s^2+40s+3
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
Write the equation for:
(-4,0)
(0,0)
(-2,-4)
y = x^2 + 4x
A rock is thrown directly up from a treehouse: h=-16t^2+48t+20
What is the maximum height that the rock reaches?
56 feet
A tennis ball is hit: h(s)=-16s^2+40s+3
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
4. Select all equations whose graph opens upward.
y=-x^2+9x
y=10x-5x^2
y=(2x-1)^2
y=(1-x)(2+x)
y=x^2-8x-7
3 and 5
All equations with positive x^2
A rock is thrown directly up from a treehouse: h=-16t^2+48t+20
How tall is the treehouse?
20 feet
A tennis ball is hit: h(s)=-16s^2+40s+3
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
The reason why x = 3 and - 10 for: are solutions for:
(x - 3)(x + 10) = 0
EXPLAIN...
The factors will add up to 0 when you use the x answers.