4.2 stations

Station 1
A weight 2 feet above the ground on a carnival strength test is shot in the air with an initial velocity
of 32 ft/sec where t represents the time in seconds the weight is in the air.
Approximately how long does the weight take to reach a height of 10 feet on the way up?
Solve both graphically and another algebraic way.
Station 1 key
Graphically:
Alternate method: (quadratic formula)
10 = βˆ’16𝑑 2 + 32𝑑 + 2
βˆ’16𝑑 2 + 32𝑑 βˆ’ 8 = 0 (now divide by -8)
2𝑑² βˆ’ 4𝑑 + 1 = 0
π‘₯=
4 ± √16 βˆ’ 4(2)(1)
4
π‘₯=
4 ± 2√2 2 ± √2
=
= 0.2928 π‘Žπ‘›π‘‘ 1.707
4
2
0.2928 represents the way up
Station 2
A rocket is launched from atop a 63-foot cliff with an initial velocity of 102 ft/s.
a. What is the vertical motion equation that represents this situation?
b. How long will the rocket take to hit the ground (not the cliff) after it is launched? Round to the nearest
hundredth. Use your calculator.
c. At what time does the rocket reach its maximum height?
d. There is a bird in the sky 75 feet above the cliff. Is it possible for the rocket to injure the bird? If yes, then
at what time after the rocket is launched should the bird be worried? Use the table to tell between what time
intervals the bird might need to put on a safety helmet.
Station 2 key
a. β„Ž = βˆ’16𝑑 2 + 102𝑑 + 63
b. use 0 for h, t = 6.94 seconds
c. 3.19 seconds
d. 63 + 75 = 138, so we are looking for the times when the parabola is at 138 feet. If you look at
the table, the y value is 138 between 0 and 1 second and also between 5 and 6 seconds.
Station 3
1. The discriminant of a function is 32. Which could be a graph of the function?
A
C
B
D
2. When does the equation π‘₯ 2 = 𝑑 have no solutions?
A always
B when d 0 C Never
D when d 0
3. Determine how many solutions each equation has:
a) 4π‘₯ 2 βˆ’ 5π‘₯ + 7 = 10
b) βˆ’3π‘₯ 2 βˆ’ π‘₯ + 4 = 5
c) βˆ’π‘₯ 2 βˆ’ 2π‘₯ βˆ’ 1 = 0
Station 3 key
1. C
2. B
3. A) 𝑏² βˆ’ 4π‘Žπ‘ > 0 π‘ π‘œ π‘‘β„Žπ‘’π‘Ÿπ‘’ π‘Žπ‘Ÿπ‘’ 2 π‘Ÿπ‘’π‘Žπ‘™ π‘ π‘œπ‘™π‘’π‘‘π‘–π‘œπ‘›π‘ 
B) 𝑏² βˆ’ 4π‘Žπ‘ < 0 π‘ π‘œ π‘‘β„Žπ‘’π‘Ÿπ‘’ π‘Žπ‘Ÿπ‘’ π‘§π‘’π‘Ÿπ‘œ π‘Ÿπ‘’π‘Žπ‘™ π‘ π‘œπ‘™π‘’π‘‘π‘–π‘œπ‘›π‘ 
C) 𝑏² βˆ’ 4π‘Žπ‘ = 0 π‘ π‘œ π‘‘β„Žπ‘’π‘Ÿπ‘’ 𝑖𝑠 1 π‘Ÿπ‘’π‘Žπ‘™ π‘ π‘œπ‘™π‘’π‘‘π‘–π‘œπ‘›
Station 4
Solve using any method except graphing:
You are helping to install a square patio for a service project. Around the patio will be a
sidewalk that is 3 feet wide. The total area of the patio and sidewalk will be 400 square
feet. What are the dimensions of the patio?
Station 4 key
Solve using square roots:
(π‘₯ + 6)2 = 400
√(π‘₯ + 6)2 = √400
π‘₯ + 6 = ±20
π‘₯ = ±20 βˆ’ 6 π‘ π‘œ π‘₯ = 14 π‘Žπ‘›π‘‘ π‘₯ = βˆ’26
𝑀𝑒 π‘‘π‘œπ‘›β€² 𝑑 𝑒𝑠𝑒 βˆ’ 26, π‘ π‘œ π‘₯ = 14 π‘Žπ‘›π‘‘ π‘‘β„Žπ‘’ π‘‘π‘–π‘šπ‘’π‘›π‘ π‘–π‘œπ‘›π‘  π‘œπ‘“ π‘‘β„Žπ‘’ π‘π‘Žπ‘‘π‘–π‘œ π‘Žπ‘Ÿπ‘’ 14 𝑓𝑒𝑒𝑑 𝑏𝑦 14 𝑓𝑒𝑒𝑑
Station 5
Solve using the quadratic formula. Write answers in simplest radical form.
1. 6π‘Ž2 βˆ’ 2𝑛 βˆ’ 8 = βˆ’5
2. 4𝑏 2 βˆ’ 3𝑏 = 10
3. 5𝑓 2 βˆ’ 𝑓 βˆ’ 1 = 0
Station 5 key
1. 6π‘Ž2 βˆ’ 2𝑛 βˆ’ 8 = 5
π‘₯=
2 ± √4 βˆ’ 4(6)(βˆ’3) 2 ± √76 2 ± 2√19 1 ± √19
=
=
=
12
12
12
6
2. 4𝑏 2 βˆ’ 3𝑏 = 10
π‘₯=
3±βˆš9βˆ’4(4)(βˆ’10)
3. 5𝑓 2 βˆ’ 𝑓 βˆ’ 1 = 0
π‘₯=
1±βˆš1βˆ’4(5)(βˆ’1)
8
10
=
=
3±βˆš169
8
1±βˆš21
10
=
3±13
8
π‘ π‘œ π‘₯ = 2 π‘Žπ‘›π‘‘ π‘₯ =
βˆ’5
4
Station 6
1
The function 𝑔(π‘₯ ) is graphed below. If 𝑔(π‘₯ ) = (π‘₯ + 2)2 βˆ’ 2, what are the values of x when 𝑔(π‘₯ ) = 6?
2
Describe 2 different methods of answering this question.
Station 6 key
Graphically:
When g(x) = 6, what are the x values? What are the x values when y = 6? Look at the graph to find the
appropriate x values at y = 6. The x values are 2 and -6.
Algebraically:
6=
1
(π‘₯ + 2)2 βˆ’ 2
2
1
6 = (π‘₯ 2 + 4π‘₯ + 4) βˆ’ 2
2
1
6 = ( π‘₯ 2 + 2π‘₯ + 2) βˆ’ 2
2
1 2
π‘₯ + 2π‘₯ βˆ’ 6 = 0
2
π‘₯ 2 + 4π‘₯ βˆ’ 12 = 0
(π‘₯ + 6)(π‘₯ βˆ’ 2) = 0
π‘₯ = βˆ’6 π‘Žπ‘›π‘‘ 2
Station 7
Solve by completing the square. Round to the nearest hundredth if necessary.
1. 4𝑓 2 + 16𝑓 βˆ’ 100 = 0
2. π‘₯² + 8π‘₯ + 5 = βˆ’4
3. 3π‘₯² + 6π‘₯ + 5 = 12
Station 7 key
1. 4𝑓 2 + 16𝑓 βˆ’ 100 = 0
𝑓 2 + 4𝑓 βˆ’ 25 = 0
𝑓 2 + 4𝑓 + 4 = 25 + 4
(𝑓 + 2)2 = 29
√(𝑓 + 2)2 = √29
𝑓 + 2 = ±βˆš29
𝑓 = βˆ’2 ± √29 = βˆ’7.39 π‘Žπ‘›π‘‘ 3.39
2. π‘₯² + 8π‘₯ + 5 = βˆ’4
π‘₯² + 8π‘₯ + 16 = βˆ’9 + 16
(π‘₯ + 4)² = 7
√(π‘₯ + 4)2 = √7
π‘₯ + 4 = ±βˆš7
π‘₯ = βˆ’4 ± √7 = βˆ’6.65 π‘Žπ‘›π‘‘ βˆ’ 1.35
3. 3π‘₯² + 6π‘₯ + 5 = 12
π‘₯ 2 + 2π‘₯ + 1 =
(π‘₯ + 1)2 =
7
+1
3
10
3
10
10
π‘₯ + 1 = ±βˆš = βˆ’1 ± √ = βˆ’2.83 π‘Žπ‘›π‘‘ 0.83
3
3
Station 8
Solve using square roots. Write answers in simplest radical form.
Don’t forget to rationalize the denominator!
1. 5π‘š² = 12
2. 9π‘₯ 2 = 200
3. 3𝑏² = 25
Station 8 key
1. 5π‘š² = 12
βˆšπ‘š² = √
12
5
±2√3 √5 ±2√15
π‘š=
βˆ™
=
5
√5 √5
2. 9π‘₯ 2 = 200
√π‘₯² = √
200
9
±10√2
π‘₯=
3
3. 3𝑏² = 25
βˆšπ‘² = √
𝑏 = ±βˆš
25
3
25 ±5 √3 ±5√3
=
βˆ™
=
3
3
√3 √ 3