Unit 11B - Trigonometry Flashcards
What are the reference angles? (3)
- Acute angle formed
- By terminal side & x - axis
- How far away are you from the x- axis?
Definition of Standard Position
An angle is in standard position when its initial side is on the positive x - axis
Definition of Initial Side (2)
- Doesn’t move
- Is on positive x - axis in standard position
Definition of Terminal Side (2)
- Moves as the angle measure changes
- Determines the quadrant where the angle is
What are the quadrantal angles?
- 0°
- 90°
- 180°
- 270°
- 360°
- 450°
Definition of Unit Circle
Definition: Circle with radius of 1 and centered at the origin
Functions: Cos𝜃 = X, Sin𝜃 = Y, Tan𝜃 = Y/X
Coordinates: 0° & 360° = (1,0), 90° = (0,1), 180° = (-1, 0), 270° = (0, -1)
Definition of ASTC Chart?
Tells you which function is positive in that quadrant
What is the acronym to remember the order of ASTC?
All Students Take Classes
What is something to keep in mind about reciprocal functions in ASTC?
Reciprocal functions hold the same sign value as original functions
In right triangle ABC, angle A = 90.
If b = 3.64 and a = 7.28, find angle b.
What does a & b mean in the context of the problem?
a & b are sides of the triangle.
a is the side opposite of angle a
b is the side opposite of angle b
What is QRS?
Quadrant
Reference Angle
Sign (+ or -)
(Used to find exact values of functions & their angles)
What is the law of sines? (3)
- a/sinA = b/sinB
- Applies to all triangles (not only right)
- Use Opposites - Opp. of sinA will be side a (a/sinA)
(Must be Given 2 angles & 1 Side or 2 Sides & 1 angle)
What is the law of cosines? (4)
- 𝑐2=𝑎2 + 𝑏2 − 2𝑎𝑏 ⋅ cos(C)
- Both ends of the equation must always have the matching side & ∠
- Use if there’s no angles given and no opposites
- Look for SSS or SAS
(Must be Given 2 Sides & 1∠ or 3 Sides)
What does it mean when you are solving a trig equation? How? (1/6)
- Find the measure of an angle in a specified interval that makes the trig eq. true
- Treat trig function as a variable
- Solve equation
- Find the reference angle using the exact value table
- Instantly convert it to radians
- Decide which quadrants angles could be using ASTC
- Draw “Bow - Tie” and use Reference Angles to find Angle in Radians