Grade 12 Pre-Calculus Mathematics [MPC40S] Chapter 4 Trigonometry and the Unit Circle Outcomes T1, T2, T3, T5 12P.T.1. Demonstrate an understanding of angles in standard position expressed in degrees and radians. 12P.T.2. Develop and apply the equation of the unit circle. 12P.T.3 Solve Problems, using the six trigonometric ratios for angles expressed in radians and degrees. 12P.T.5. Solve, algebraically and graphically, first and second-degree trigonometric equations with the domain expressed in degrees and radians.
34
Embed
Grade 12 Pre-Calculus Mathematics [MPC40S] Chapter 4 ...Coterminal Angles are _____ _____ Example #12 Sketch π=30Β° as an angle in standard position, and show that π=390Β° and
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Grade 12 Pre-Calculus Mathematics
[MPC40S]
Chapter 4
Trigonometry and the Unit Circle
Outcomes
T1, T2, T3, T5
12P.T.1. Demonstrate an understanding of angles in standard position expressed in degrees and radians. 12P.T.2. Develop and apply the equation of the unit circle. 12P.T.3 Solve Problems, using the six trigonometric ratios for angles expressed in radians and degrees. 12P.T.5. Solve, algebraically and graphically, first and second-degree trigonometric equations with the domain expressed in degrees and radians.
MPC40S Date: ____________________
Pg. #2
MPC40S Date: ____________________
Pg. #3
Chapter 4 β Homework
Section Page Questions
MPC40S Date: ____________________
Pg. #4
MPC40S Date: ____________________
Pg. #5
Chapter 4: TRIGONOMETRY AND THE UNIT CIRCLE
4.1 β Angles and Angle Measure An _______________________________________________ has its centre at the origin and its initial arm along the positive x-axis There are ____________________ and ___________________ angles. Positive Angles Negative Angles (Counter-clockwise) (Clockwise)
T1
MPC40S Date: ____________________
Pg. #6
Example #1
In which quadrant is the terminal arm of each angle located? a) 400Β° _______ b) 700Β° _______ c) β 65Β° _______ d) β 150Β° _______ Example #2
Sketch each angle in standard position. a) 286Β° b) β190Β° c) 430Β°
MPC40S Date: ____________________
Pg. #7
Radian Measure of an Angle
The formula for the circumference of a circle is _______________
The unit circle has a radius = __________
Therefore, the circumference of the unit circle is ____________ 2Ο = 6.283185β¦ This means that the distance traveled from the initial arm all around the circle and back again is 6.283185β¦
Revolutions Degrees Radian Measure
1 revolution _____ radians 6.283185β¦ radians
1
2 revolution _____ radians 3.141592β¦ radians
1
4 revolution _____ radians 1.570796β¦ radians
3
4 revolution _____ radians 4.712388β¦ radians
1
360 revolution _____ radians 0.017453β¦ radians
Note that 1 radian = (180Β°
π) β 57.3Β°
MPC40S Date: ____________________
Pg. #8
Converting Degrees to Radians: __________________________
Example #3
Express the following angle measures in radians. a) 30Β°
b) 225Β° c) 720Β°
Converting Radians to Degrees: __________________________
Example #4
Express the following angle measures in degrees
a) 2π
3
b) 1.6 c) 5π
6
MPC40S Date: ____________________
Pg. #9
Coterminal Angles Coterminal Angles are ___________________________________________________ ______________________________________________________________________ Example #12
Sketch π = 30Β° as an angle in standard position, and show that π = 390Β° and π =β330Β° are coterminal angles. The coterminal angle can be found by adding or subtracting revolutions; either Β±360Β° when given degree measure or Β±2π when given radian measure. There are an infinite number of coterminal angles. Example #5
Determine 3 coterminal angles for 40Β°. Example #6
Determine 3 coterminal angles for π
6
MPC40S Date: ____________________
Pg. #10
General Form of Coterminal Angles Degrees: ________________________ Radians: ________________________
Example #7
Express the angles coterminal with 50Β° in general form.
Example #8
Express a general form for all coterminal
angles of 5π
3
Example #9
Determine a coterminal angle to 740Β° over the interval β360Β° < π < 0Β° Example #10
Determine all coterminal angles to 5π
3 over the interval [β4π, 2π]
MPC40S Date: ____________________
Pg. #11
Arc Length The central angle is the relationship between the length of the arc and the radius of the circle. The equation that represents this relationship is:
Note: If there is no unit attached to the angle measure (ex: π = 2.5) it is assumed to be in radians. Example #11
Determine the arc length. Example #12
A bicycle tire has a radius of 0.5 m and travels a distance of 1.5 m. Determine the rotated angle, in degrees.
s
MPC40S Date: ____________________
Pg. #12
Example #13
Given the following information determine the missing value. a) π = 8.7 cm, π = 75Β° determine arc length b) π = 1.8, π = 4.7 mm, determine the radius c) π = 5 m, π = 13 m, determine the measure of the central angle
MPC40S Date: ____________________
Pg. #13
Chapter 4: TRIGONOMETRY AND THE UNIT CIRCLE
4.2 β The Unit Circle The unit circle is centered at the origin and has a radius of 1 unit. We use the notation π(π) to indicate a point on the circle. π = arc length π(π) = defined by a point (π₯, π¦)
Since the radius is 1, then the equation of the unit circle is π₯2 + π¦2 = 1 Important ideas: _________________________________________________________ _________________________________________________________
T2 T3
MPC40S Date: ____________________
Pg. #14
Example #1
Determine whether or not the point (2
5,
3
5) is on the unit circle. Justify your reasoning.
Example #2
A point (2
3, π¦) is on the unit circle. Determine the value of y.
MPC40S Date: ____________________
Pg. #15
Example #3
The point π(π) lies on the intersection of the unit circle and a line joining the origin to the
point (4, 3). Determine the coordinates of π(π).
MPC40S Date: ____________________
Pg. #16
Example #4
The point π(π) lies on the intersection of the unit circle and a line joining the origin to the point (β3, 6). Determine the coordinates of π(π).
MPC40S Date: ____________________
Pg. #17
Example #5
Determine the values of cos π and tan π over the interval 3π
2β€ π β€ 2π when sin π = β
3
5.
MPC40S Date: ____________________
Pg. #18
MPC40S Date: ____________________
Pg. #19
Chapter 4: TRIGONOMETRY AND THE UNIT CIRCLE
The Unit Circle
QUADRANT 1
MPC40S Date: ____________________
Pg. #20
π
3 Family
π
4 Family
π
6 Family
MPC40S Date: ____________________
Pg. #21
THE UNIT CIRCLE
MPC40S Date: ____________________
Pg. #22
MPC40S Date: ____________________
Pg. #23
Chapter 4: TRIGONOMETRY AND THE UNIT CIRCLE
4.3 β Trigonometric Ratios Recall: π = arc length π(π) = defined by a point (π₯, π¦)
If we use the trigonometric rations SOH CAH TOA, then
sin π =π¦
1 β ____________
cos π =π₯
1 β _____________
tan π =
π¦
π₯ β _____________
Thus, any point on the unit circle can be described as: π(π) = (cos π , sin π)
PRIMARY FUNCTIONS RECIPROCAL FUNCTIONS (1
π(π₯))
sin π = π¦ cosecant _____________________ cos π = π₯ secant _____________________
tan π =π¦
π₯ cotangent _____________________
T2 T3
MPC40S Date: ____________________
Pg. #24
Example #1
The point (5
13, β
12
13) lies on the terminal arm of an angle ΞΈ in standard position.
a) Draw a diagram to represent this situation. b) Find all 6 trigonometric ratios for ΞΈ. Example #2
The point (β3
5,
4
5) lies on the terminal arm of an angle ΞΈ in standard position.
a) Draw a diagram to represent this situation. b) Find all 6 trigonometric ratios for ΞΈ.
MPC40S Date: ____________________
Pg. #25
Determining Exact Values Example #3
Determine the exact value of the following trigonometric ratios.
a) cosπ
3= b) sec
π
3=
c) sin (β5π
6) =
d) cos7π
4=
e) cot(270Β°) =
f) csc (2π
3) =
g) tan17π
4=
h) sec23π
3=
MPC40S Date: ____________________
Pg. #26
Example #4
Determine the exact value of the following expressions. a) cos(120Β°) β tan(β135Β°)
b) cot (β3π
4) + csc (
π
2)
c) sin2 (7π
6) + cos2 (
7π
6)
d) tan2 (βπ
3) sec (
4π
3)
MPC40S Date: ____________________
Pg. #27
Chapter 4: TRIGONOMETRY AND THE UNIT CIRCLE
4.4 β Trigonometric Equations We can solve trigonometric equations just like we have been solving equations from previous units. Note: If interval/domain is given in radians, your answer must be in radians. If interval/domain is given in degrees, your answer must be in degrees. Example #1
Solve the following trigonometric equation, over the given domain.
sin π =1
2, 0 β€ π β€ 2π
Example #2
Solve the following trigonometric equations, over the given domain. a) 2 cos π + 3 = 1, 0Β° β€ π β€ 540Β° b) 4 sec π₯ + 8 = 0, 0 β€ π₯ β€ 2π
T5
MPC40S Date: ____________________
Pg. #28
Example #3
Solve the following trigonometric equations, over the given intervals.
a) 3tan2π₯ β 9 = 0, 0Β° β€ π₯ β€ 360Β°
b) 2cos2π + cos π = 1, 0 β€ π β€ 2π
MPC40S Date: ____________________
Pg. #29
Example #4
Solve the following trigonometric equations, over the given intervals.
a) 2sin2π₯ β 1 = sin π₯, 0 β€ π₯ β€ 270Β°
b) sin2π₯ + sin π₯ β 12 = 0, 0 β€ π₯ β€ 2π
MPC40S Date: ____________________
Pg. #30
Example #5
Solve the following trigonometric equations, over the given intervals.
General Solution of Trigonometric Equations If the domain is real numbers, there are an infinite number of rotations on the unit circle in both a positive and negative direction. To determine a general solution, find the solutions in one positive rotation. Then use the concept of coterminal angles to write an expression that identifies all possible measures. There are different was to request the general solution answers. They are:
Domain is all real numbers
π₯ β π or π β π
General solution Example #7
a) Solve cot π =1
β3 over the interval 0 β€ π β€ 2π
b) Solve the above equation if π β π
MPC40S Date: ____________________
Pg. #33
Example #8
Solve each of the following trigonometric equations. a) Solve tan π = β4 if the domain is all real numbers, in radians.
b) Find the general solution of cos π½ = 0, in degrees.
MPC40S Date: ____________________
Pg. #34
Example #9
Solve the following trigonometric equation, where π β π . (In radians)