# 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 Trigonometry Identities Question and Answer Set 1**. 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 Question 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 Question 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 Question 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 Question 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 Question 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**