JEE Advanced2017MathematicsVector AlgebraActual
Paragraph: Let O be the origin, and O X , O Y , O Z be three unit vectors in the directions of the sides Q R , R P , P Q , respectively, of a triangle P Q R . Question: | O X O Y |=
Options
- Asin P + Q
- Bsin   2 R
- Csin P + R
- Dsin Q + R
Correct answer
A. sin P + Q
Step-by-step solution
O X → ,   O Y → ,   O Z → are unit vectors in the directions of sides O R → ,   R P → and P Q → respectively, ∴    O X → = Q R → Q R → ,    O Y → = R P → R P → ,   O Z → = P Q → P Q →   ∴    O X → × O Y → = O R → × R P → Q R →   R P → = Q R →   R P → sin P + Q Q R →   R