Ch 9

Question 1

Trigonometry def

Answer 1

The word trigonometry has been derived from three greek words: trei (three), goni(angles), metron (measurement). It literally means measurement of triangle.

Question 2

No. Of Fundamental identities

Answer 2

3

Question 3

Fundamental identities

Answer 3

Sin²θ+cos²θ=1
1+tan²θ=sec²θ
1+cot²θ=cosec²θ

Question 4

1+cot²θ=?

Answer 4

cosec²θ

Question 5

1+tan²θ=?

Answer 5

sec²θ

Question 6

Sin²θ+cos²θ=?

Answer 6

1

Question 7

sec²θ-tan²θ=?

Answer 7

1

Question 8

Formula to find L

Answer 8

L=rθ

Question 9

Dgree to radian formula

Answer 9

Pi/180

Question 10

Radian to degree formula

Answer 10

180/pi

Question 11

D⁰M’S’’ to decimal

Answer 11

D⁰+M’/60+S”/3600

Question 12

Decimal to D⁰M’S”

Answer 12

D⁰+0.??×60 if ans in decimal again then multiply value after point by 60

Question 13

Radian def

Answer 13

It is the measure of angle subtended at the centre of the circle by an arc, whose length is equal to the radius of the circle

Question 14

Standard position def

Answer 14

Angle is said to be in a standard position if its vertex lies at the origin of the rectangular coordinate system and its initial side along positive x axis

Question 15

Sin(-θ)

Answer 15

-sinθ

Question 16

Csc(-θ)

Answer 16

-cscθ

Question 17

Cos(-θ)

Answer 17

Cosθ

Question 18

Sec (-θ)

Answer 18

Secθ

Question 19

Tan(-θ)

Answer 19

-tanθ

Question 20

Cot(-θ)

Answer 20

-cotθ

Question 21

Sin 45

Answer 21

1/√2

Question 22

Cos45

Answer 22

1/√2

Question 23

Tan45

Answer 23

1

Question 24

Sin30

Answer 24

1/2

Question 25

Cos30

Answer 25

√(3)/2

Question 26

Tan30

Answer 26

1/√3

Question 27

Sin60

Answer 27

√3/2

Question 28

Cos60

Answer 28

1/2

Question 29

Tan60

Answer 29

√3

Question 30

Tan60

Answer 30

√3

Question 31

Table angles?

Answer 31

0,30,45,60,90

Question 32

Quadrantal angles def

Answer 32

The angles that lie on x and y axis are called quadrantal angles 0,90,180,270,360

Question 33

Sin0

Answer 33

0

Question 34

Cos0

Answer 34

1

Question 35

Tan0

Answer 35

0

Question 36

Sin90

Answer 36

1

Question 37

Cos90

Answer 37

0

Question 38

Tan90

Answer 38

Undefined

Question 39

Sin180

Answer 39

0

Question 40

Cos180

Answer 40

-1

Question 41

Tan180

Answer 41

0

Question 42

Sin270

Answer 42

-1

Question 43

Cos270

Answer 43

0

Question 44

Tan270

Answer 44

Undefined

Question 45

(√2)/2

Answer 45

1/√2

Question 46

2/√2

Answer 46

√2

Question 47

Co terminal angle

Answer 47

The angles with the same in initial and terminus sides are called co terminal angles. I.e θ, θ±2π, θ±4π are co terminal angles, where 0≤θ≤2π

Question 48

General angle

Answer 48

The angle θ+2kπ or θ-2kπ, where k € Z and 0≤θ≤2π is called general angle