Trigonometry

Question 1

SOH CAH TOA

right triangle

Answer 1

sin θ = opposite/hypotenuse
cos θ = adjacent/hypotenuse
tan θ = opposite/adjacent

opposite : side opposite of angle

Question 2

sine

unit circle

Answer 2

sin θ = y

y-coefficient

Question 3

cosine

unit circle

Answer 3

cos θ = x

x-coefficient

Question 4

tangent

unit circle

Answer 4

tan = sin/cos
tan = y/x

Question 5

cotangent

unit circle

Answer 5

cot = cos/sin
cot = x/y

reciprocal of tangent

Question 6

signs of trig functions per quadrant

Answer 6

ASiTaCo

moves counter-clockwise (Q1, Q2, Q3, Q4)

Q1 : ALL positive
Q2: SINE/COSECANT positive
Q3: TANGENT/COTANGENT positive
Q4: COSINE/SECANT positive

Question 7

radians to degrees

Answer 7

radian x 180/π

pi will cancel out

Question 8

degrees to radians

Answer 8

degree x π/180º

degrees will cancel out

Question 9

left hand technique

sine

Answer 9

sin = √# of fingers / 2

of fingers on top

Question 10

left hand technique

cosine

Answer 10

cos = √# of fingers / 2

of fingers on the bottom

Question 11

left hand technique

tangent

Answer 11

tan = √# of fingers taas /
√# of fingers baba

of fingers on the bottom

Question 12

trig values of reference angles

acute angle formed by terminal side and x-axis

Answer 12

same reference angle = same trig values

different signs (asitaco)

Question 13

looking for

coterminals

terminal side is on same location

Answer 13

add or subtract 360 until
0 ≤ θ ≤ 360

Question 14

reciprocal of sin θ

Answer 14

1 / csc θ

cosecant

Question 15

reciprocal of cos θ

Answer 15

1 / sec θ

secant

Question 16

reciprocal of tan θ

Answer 16

1 / cot θ

cotangent