AP EAMCET202125 Aug 2021Morning ShiftMathematicsVector AlgebraActual
If is the angle between the unit vectors a and b , then 2 is equal to
Options
- A| a - b a + b |
- B| a + b |
- C| a - b |
- D1 2 | a - b |
Correct answer
D. 1 2 | a - b |
Step-by-step solution
aligned & Given, | a |=| b |=1 & | a - b |^2=| a |^2+| b |^2-2| a || b | & | a - b |^2=1+1-2 & | a - b |^2=2(1- ) & | a - b |^2=2 (2 ^2 ( 2 ) ) & ^2 2 = 1 4 | a - b |^2 & 2 = 1 2 | a - b | & aligned