# Sum And Difference Identities Question and Answer Set 1

Hi students, welcome to **Amans Maths Blogs (AMB)**. On this post, you will get the Sum And Difference Identities Question and Answer Set 1 is the collection of some important questions. Practice these questions for SSC CAT NTSEexams etc. It will help you to practice the questions on the topics of inverse trigonometric functions based questions with answers.

**Sum And Difference Identities Question and Answer Set 1: Ques No 1**

The value of sin(A + B) – sin(A – B) is

**Options:**

A. 2cosAsinB

B. 2sinAsinB

C. 2cosAcosB

D. 2sinAcosB

**Answer: A**

**Sum And Difference Identities Question and Answer Set 1: Ques No 2**

If sinA = 3/5 and sinB = 12/13, where A and B are acute angles, then the value of cos(A + B) is

**Options:**

A. 16/65

B. 65/65

C. -16/65

D. -56/65

**Answer: C**

**Sum And Difference Identities Question and Answer Set 1: Ques No 3**

The value of tan 75^{0} is

**Options:**

A. 2 + Root(3)

B. 1 + Root(2)

C. 2 – Root(3)

D. 1 – Root(2)

**Answer: A**

**Sum And Difference Identities Question and Answer Set 1: Ques No 4**

Which of the following is NOT equal to cos(20 + 50)cos50 + sin(20 + 50)sin(50)?

**Options:**

A. cos20

B. sin70

C. -cos160

D. -sin160

**Answer: D**

**Sum And Difference Identities Questions and Answer Set 1: Ques No 5**

Which of the following is equal to [Root(3)cosx – sinx]/2?

**Options:**

A. cosx

B. sinx

C. cos(30 + x)

D. sin(30 + x)

**Answer: C**

**Sum And Difference Identities Questions and Answer Set 1: Ques No 6**

The cos(30º – A).cos(30º + A) + cos(45º + A).cos(45º – A) – cos2A is

**Options:**

A. 1/2

B. 1/3

C. 1/4

D. 1/5

**Answer: C**

**Sum And Difference Identities Questions and Answer Set 1: Ques No 7**

If cos(A + B) = 4/5 and sin(A – B) = 5/13 where 0 < A, B < Pi/4, then the value of cot2A is

**Options:**

A. 12/19

B. 7/20

C. 19/25

D. 33/56

**Answer: D**

**Sum And Difference Identities Questions and Answer Set 1: Ques No 8**

If tanx = m/(m + 1) and tany = 1/(2m + 1), then the value of (x + y) is

**Options:**

A. Pi/4

B. -Pi/4

C. 3Pi/4

D. -3Pi/4

**Answer: A**

**Sum And Difference Identities Questions and Answer Set 1: Ques No 9**

If cos(x – y) = acos(x + y), then the value of cotxcoty is

**Options:**

A. (a – 1)/(a + 1)

B. (a + 1)/(a – 1)

C. a – 1

D. a + 1

**Answer: B**

**Sum And Difference Identities Questions and Answer Set 1: Ques No 10**

If sinA = 13/14 and sinB = 11/14 for 0 < A < Pi/2 and 0 < B < Pi/2, then the value of (A + B) is

**Options:**

A. 60 degree

B. 30 degree

C. 120 degree

D. 150 degree

**Answer: C**

**Sum And Difference Identities Questions and Answer Set 1: Ques No 11**

If [tan(x + 120^{o})]/[tan(x – 30^{o})] = 11/2 and cos4x = a/b, where a and b are coprime positive integers, then the value of (a + b) is

**Options:**

A. 162

B. 164

C. 167

D. 169

**Answer: D**

**Sum And Difference Identities Questions and Answer Set 1: Ques No 12**

If A = Pi/5, then the value of tanAtan2A + tan2Atan3A + … tan8Atan9A is

**Options:**

A. -10

B. -14

C. -22

D. -26

**Answer: A**

**Sum And Difference Identities Questions and Answer Set 1: Ques No 13**

The value of sin(A – B)/sinAsinB + sin(B – C)/sinBsinC + sin(C – A)/sinCsinA is

**Options:**

A. -2

B. -1

C. 0

D. 1

**Answer: C**

**Sum And Difference Identities Questions and Answer Set 1: Ques No 14**

The value of cos2θcosϕ + sin^{2}(θ – ϕ) – sin^{2}(θ + ϕ) is

**Options:**

A. cos2(θ + ϕ)

B. sin2(θ – ϕ)

C. sin2(θ + ϕ)

D. cos2(θ – ϕ)

**Answer: A**