1. 1.5/2
Determine the equivalent positive standard-position angle for each
negative angle listed below. (2 marks: 1 mark each)
a. −98∘
360 °−98 °=262 °
b.
−π
3
−π 180 −180 π
× = =−60 °
3 π 3π
360 °−60 °=300 °
[This question was given in radians, so the answer should also be in
radians.]
2. 3/4
Solve cotθ=1.6 for the domain 0≤θ≤360∘. Round your answer to
the nearest degree. (4 marks: 1 mark for the correct value of
tanθ; 1 mark for the correct related acute angle; and 1 mark
each for the correct standard-position angles)
cotθ=1.6
1 1
= =0.625
tanθ 1.6
, ta n−1 ( 0.625 )=32 °
°
Standard-position angle for domain 0≤θ≤360 .
32°
Note: Related Acute Angle (RA) = √
Quadrant 1:
0 ° +32° = 32°
Quadrant 2:
180 ° – 32° = 148 °
Quadrant 3:
180 °+32 °=¿ 212 °
Quadrant 4:
360 ° – 32°=328 °
[The tan ratio is only positive in quadrants 1 and 3; therefore, the angles
are 32o and 212o only.]
3. 3/3
Use the unit circle to evaluate the following trigonometric ratios.
Show your calculations. (3 marks: 1 mark each)
x=0, y=1, r=1
a. sin90∘,
y 1
sin 90 °= = =1
r 1
, x=−1, y =0, r=1
b. cosπ,
x −1
cosπ = = =−1
r 1
3π
csc ( ) , x =0, y=−1,r =1
c. 2
csc ( 32π )= sinθ1 = ry = −11 =−1
4. 2/2
Convert the following angles from degrees to radians. Leave your
answers in exact form. (2 marks: 1 mark each)
a. 220∘
220 π 11 π
× = radians
1 180 9
b. 48∘
48 π 4π
× = radians
1 180 15
5. 1.5/2
Convert the following angles from radians to degrees. Round your
answers to the nearest degree. (2 marks: 1 mark each)
3π
a. 4
3 π 180 3 π × 180 540 π
× = =
4 π 4π 4π