If sin(A – B) = 0, where 0° ≤ A, B ≥ 90° then find the val

1.	If sin(A – B) = 0, where 0° ≤ A, B ≥ 90° then find the value of 2sinA × sinB + 2cosA × cosB 1. Even prime number less than 52. 23. 14. Both options 1 and 2 are correct
Answer» Correct Answer - Option 4 : Both options 1 and 2 are correct Given: Value of sin(A – B) = 0 Identity used: sin²A + cos²A = 1 Calculation: As, sin(A – B ) = 0 ⇒ sin(A – B ) = sin0° ⇒ A – B = 0 ⇒ A = B We have to find the value of 2sinA × sinB + 2cosA × cosB ⇒ 2sinA × sinB + 2cosA × cosB = 2 × (sinA × sinA + cosA × cosA) ⇒ 2 × (sin²A + cos²A) ⇒ 2 Now 2 is also the even prime number less than 5. ∴ Both options 1 and 2 are correct.

If sin(A – B) = 0, where 0° ≤ A, B ≥ 90° then find the value of 2sinA × sinB + 2cosA × cosB 1. Even prime number less than 52. 23. 14. Both options 1 and 2 are correct

Answer» Correct Answer - Option 4 : Both options 1 and 2 are correct

Given:

Value of sin(A – B) = 0

Identity used:

sin²A + cos²A = 1

Calculation:

As, sin(A – B ) = 0

⇒ sin(A – B ) = sin0°

⇒ A – B = 0

⇒ A = B

We have to find the value of 2sinA × sinB + 2cosA × cosB

⇒ 2sinA × sinB + 2cosA × cosB = 2 × (sinA × sinA + cosA × cosA)

⇒ 2 × (sin²A + cos²A)

⇒ 2

Now 2 is also the even prime number less than 5.

∴ Both options 1 and 2 are correct.