High School Mathematics - 2 10.18 Trignometry Review

Function

0^{o}

30°

45°

60°

90°

sin

Ö0/2

Ö1/2

Ö2/2

Ö3/2

Ö4/2

cos

Ö4/2

Ö3/2

Ö2/2

Ö1/2

0

tan

0

Ö3/3

1

Ö3

undefined

sec

1

2Ö3/3

Ö2

2

undefined

csc

undefined

2

Ö2

2Ö3/3

1

cot

undefined

Ö3

1

Ö3/3

0

sin

cos

tan

0

0

1

0

90

1

0

infinity

180

0

-1

0

270

-1

0

infinity

Functions of angles in all quadrants in terms of those in quadrant 1

-A

90^{0} ± A P/2 ± A

180^{0} ± A P ± A

270^{0} ± A 3P/2 ± A

360^{0} ± A 2P ± A

sin

-sinA

cos A

±sin A

-cosA

±sin A

cos

cos A

±sin A

-cos A

±sin A

cos A

tan

-tan A

±cot A

± tan A

±cot A

±tan A

csc

-csc A

sec A

± csc A

-sec A

±csc A

sec

sec A

± csc A

-sec A

±csc A

sec A

cot

-cot A

± tan A

± cot A

±tan A

± cot A

Q 1: A person standing on the bank of a river, observes that the angle subtended by a tree on the opposite bank is 60 degrees, when he retires 40 metres from the bank, he finds the angle to be 30 degrees. Find the height of the tree. 20 metres 34 metres 64 metres

Q 2: cos 75^{o} Answer:

Q 3: Find the radian measure of 15^{o}. /6 /12 /4

Q 4: The horizontal distance between two towers is 60 metres and the angular depression of the top of the first as seen from the top of the second, which is 150 metres is 30^{o}. Find the height of the first. 120 metres 100 metres 115.36 metres

Q 5: The angles of a triangle ABC are in AP and b:c = 3^{1/2}:2^{1/2}. Find angle A. 45 degrees 60 degrees 75 degrees

Q 6: Find the angle in radian through which a pendulum swings if its length is 75 cm and the tip describes an arc of length 10 cm 2/15 4/15 3/15

Q 7: In triangle ABC, a = 8.4 cm, b = 7.6 cm and c = 9.2 cm. Calculate the area of triangle ABC. 50 sq. cm 45 sq cm 30 sq cm

Q 8: What is the angle of elevation of the sun when the length of the shadow of a pole is 3^{1/2} times the height of the pole? 90^{o} 60^{o} 30^{o}

Question 9: This question is available to subscribers only!

Question 10: This question is available to subscribers only!