Class 11 Maths Chapter 3 Trigonometric Functions Questions and Answers

1 Find all angles θ such that -2π < θ < 2π and cos θ = √2 / 2

A {-7 π / 4, - π / 4 , π / 4 , 7 π / 4}

B {- π / 4, - 3 π / 4 , π / 4 , 3 π / 4}

C {-5 π / 4, π / 4 , 3 π / 4}

D {π / 4 , π / 4 , 3 π / 4}

View Answer

Answer:{-7 π / 4, - π / 4 , π / 4 , 7 π / 4}

2 If sin t = 1/5 and 0 < t < π/ 2, then cos (4 t) = ?

A 0.3464

B 0.8

C 0.6928

D - 0.6928

View Answer

Answer:0.6928

3 If cos t = 1/3 and 3π /2 < t < 2π in quadrant IV, then sin (4 t) = ?

A 8 √2 / 3

B - 8 √2 / 3

C - 56 √2 / 243

D 56 √2 / 81

View Answer

Answer:56 √2 / 81

4 If cos t = 3/4, and sin t < 0, then sin (3 t) = ?

A √7 / 16

B - 5 √7 / 16

C - 3 √7 / 4

D 5 √7 / 16

View Answer

Answer:- 5 √7 / 16

5 If tan x = 5, then tan (2 x) = ?

A 10

B - 5 / 12

C 1 / 10

D 5 / 12

View Answer

Answer:- 5 / 12

6 If cos t = 0.8, then cos (2 t) = ?

A 0.28

B 0.4

C 1.0

D 1.6

View Answer

Answer:0.28

7 If sin t = 0.6 and cot t > 0, then sin (2 t) = ?

A - 0.96

B 0.48

C 0.96

D - 0.48

View Answer

Answer:0.96

8 Which of the following is not correct?

A sin(x) = -sin(-x)

B sec(-t) = sec(t)

C sin(π + x) = sin(x)

D cos(π - x) = -cos(x)

View Answer

Answer:sin(π + x) = sin(x)

9 Which of the following is not the same as tan(t)?

A - tan(-t)

B tan(t + 2π)

C tan(t + π)

D tan(t + π / 2)

View Answer

Answer:tan(t + π / 2)

10 If sin(-t) = 0.54, what is - sin(t) ?

A 0.54

B -0.54

C - 0.46

D 0.46

View Answer

Answer:0.54

11 If cos(-t) = 0.34, what is cos(t) ?

A -0.34

B 0.66

C 0.34

D - 0.66

View Answer

Answer:0.34

12 If 0 < t < π/2 and sin t = 0.65, what is sin(t + π) ?

A -0.65

B 0.65

C 0.35

D 0.76

View Answer

Answer:-0.65

13 cos(x) + cos(π - x) =?

A 2 cos(x)

B cos(x) - sin(x)

C cos(x) + sin(x)

D 0

View Answer

Answer: 0

14 If tan(t) = 13, then cot(-t) =?

A 13

B 1 / 13

C - 1 / 13

D - 13

View Answer

Answer:- 1 / 13

15 If 0 < t < π / 2 and sin t = 0.35, then cos(t + π) =?

A 0.94

B -0.94

C 0.81

D -0.81

View Answer

Answer: -0.94

16 If point (a , b) is on the Unit Circle associated with the rotation t, then the point on the Unit circle associated with rotation t + π / 2, has the following coordinates

A (b , a)

B (-b , a)

C (-b , -a)

D (-a , b)

View Answer

Answer:(-b , a)

17 If point (a , b) is on the Unit Circle associated with the rotation t and point (c , d) is also on the Unit circle associated with rotation t + π, then which of the following is correct?

A c = - a and d = - b

B c = - a and d = b

C c = a and d = b

D c = a and d = - b

View Answer