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6.7.notebook
1
May 22, 2012
May 229:26 AM
Grade 11 University Math!!!
MCR3UO
1. BELLWORK
2. 6.7 Solving 'Stuff' /w Sinusoidal Functions
Dec 62:59 PM
6.7 Modelling with Trigonometric Functions
http://www.youtube.com/watch?v=Ead8d9wVDTQ
http://www.youtube.com/watch?v=wBydVCF4DrY
Tides at the Bay of Fundy
Sound Waves
6.7.notebook
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May 22, 2012
Dec 63:02 PM
These functions can be used to model periodic phenomena
is the amplitude
is the number of cycles in 3600
or
d is the horizontal translation (phase shift)
c is the vertical translation. y = c is the horizontal axis of the graph.
REMEMBER
Dec 63:04 PM
Examples of periodic behavior:
• tides• temperatures throughout the year• populations of certain species• pendulums• ferris wheels or any (circular objects in rotation)• sound waves• etc.
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May 22, 2012
May 2210:21 AM
EX 1Chantelle is swinging back and forth on a trapeze. Her distance from a vertical support beam in terms of time can be modelled by a sinusoidal function. At 1 s, she is the maximum distance from the beam, 12 m. At 3 s, she is the minimum distance from the beam, 4 m. Determine an equation of a sinusoidal function that describes Chantelle's distance from the vertical beam in relation to time.
May 2210:22 AM
The amplitude is half the distance between the max and the min values.
(12 4)÷2 = 4
The period is the change in x that occurs as the function goes through one comlete cycle between x = 1 and x = 5 s.
period is 45 1 = 4 secondsamp is a = 4
Therefore, k = 360÷4 = 90The equation of axis is the max plus the min divided by 2.y = (12 + 4) ÷2 = 8
Shifted 1 unit to the right.Therefore, the phase shift is d = 1.
Therefore, the equation of the function is:d = 4 cos(90(t 1)) + 8
where d is distance and t is time
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May 22, 2012
Dec 63:09 PM
EX 2 The tides at Cape Capstan, New Brunswick, change the depth of the water in the harbour. On one day in October, the tides have a high point of approximately 10 m at 2 pm and a low point of approximately 1.2m at 8:15 pm. A particular sailboat has a draft of 2 m. This means that it can only move in water that is at least 2 m deep. The captain of the sailboat plans to exit the harbor at 6:30pm. Is this safe?
Dec 63:10 PM
Pg 398399 #4, 5, 6, 9
Your Work Today...
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May 22, 2012
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Dec 131:04 PM