Question

If sinA = 1/2 and cosB = 1/2 then find the value of A + B.
1. 75° 
2. 60° 
3. 120° 
4. 90° 

Answer 1

Correct Answer - Option 4 : 90° 

Given:

sinA = 1/2

cosB = 1/2

Values used:

sin30° = 1/2

cos60° = 1/2

Calculation:

sinA = 1/2 = sin30° 

⇒ A = 30° 

cosB = 1/2 = cos60° 

⇒ B = 60° 

We have to find the value of A + B

A + B = 30° + 60° 

⇒ A + B = 90° 

∴ The value of A + B is 90°