Unit 11A - Trigonometry Flashcards
How do you determine which sides are opposite, adjacent or the hypotenuse relative to an angle? (3)
- Hypotenuse - Opposite Right Angle
- Adjacent - Next to Angle
- Opposite - Only Side that Doesn’t Touch
Definition of Sine (2)
- sinθ (ratio)
- Opposite/Hypotenuse
Definition of Cosine (2)
- cosθ (ratio)
- Adjacent/Hypotenuse
Definition of Tangent (2)
- tanθ (ratio)
- Opposite/Adjacent
What is an abbreviated to remember the ratios of Sine, Cosine & Tangent?
SOH - CAH - TOA (ONLY APPLIES TO RIGHT TRIANGLES)
How do you find an side and angle measure based on cosine, sine and tangent? (3)
- Because tan, sine & cosine are considered numbers
- You can make a proportion by adding a denominator of 1
- For angle measure, multiply inverse (sin -1) by ratio
How many degrees is π equivalent to?
180 = π radians
How do you convert degrees to radians?
multiply π/180
How do you convert radians to degrees?
- Substitute π for 180 degrees
- multiply 180/π
Definition of Angle of Elevation & Angle of Depression (4)
- Angle between horizontal & line of sight
- Angle of Elevation (above)
- Angle of Depression (below)
- Angles are congruent bc horizontal lines are parallel & alt. int. angles congruent
How do you draw a horizontal line for angle of depression or angle of elevation? (3)
- Draw horizontal line from eye level of the person
- Draw a line upwards or downwards based on what they’re looking at
- When not given the height of person from “eye level”, draw horizontal from their feet
What is an instinct you must utilize when given radians for angle measure in a word problem?
Convert to Degrees
What is the reciprocal of Sine? (3)
- Cosecant
- csc (x)
- Hypotenuse/Opposite
What is the reciprocal of Cosine? (3)
- Secant
- sec (x)
- Hypotenuse/Adjacent
What is the reciprocal of Tangent? (3)
- Cotangent
- cot (x)
- Adjacent/Opposite
How do you find the ratios of csc (72), sec (72) and cot (72) in a calculator)? (3)
- csc (72) - 1/sin (72)
- sec (72) - 1/cosin (72)
- cot (72) - 1/tangent (72)
How do you find the measure of an angle of csc (x), sec (x) and cot (x)?
Convert the functions to their reciprocal functions (sin, cosin & tan) then solve!
What are Cofunctions? (5)
- Pairs of Trigonometric Functions
- Congruent when their angles are complementary
- Sine & Cosine
- Tangent & Cotangent
- Secant & Cosecant
What are the rules when it comes to cofunctions? (2)
- If Cofunctions of two angles are congruent, then the angles are complementary
- If two angles are complementary, then their cofunctions are congruent
What is the Pythagorean Identity? (3)
- sin²θ + cosin²θ = 1
- sin²θ = 1 - cos²θ
- cos²θ = 1 - sin²θ
What is the formula for tangent in trig identities?
tanθ = sinθ/cosθ
What is the formula for cotangent in trig identites?
cotθ = cosθ/sinθ
How do you simplify Trig Expressions? (5)
- Rewrite each expression in terms of sinθ and cosθ
- sin²θ + cosin²θ = 1, cscθ = 1/sinθ, secθ = 1/cosθ
- Put sinθ and cosθ over 1
- If division is involved, rewrite expression horizontally
- Utilize the Keep, Change, Flip!
What acronym helps you find the difference between the Trig Expressions Formulas for tangent and cotangent?
Tanning in South Carolina