NDA2016MathematicsTrigonometric Ratios & IdentitiesActual
What is ( 2 ) equal to?
Options
- A| a - b | 2
- B| a + b | 2
- C| a - b | 4
- D| a + b | 4
Correct answer
A. | a - b | 2
Step-by-step solution
aligned | a - b |^2 & =( a - b ) ( a - b ) & = a a - b a - a b + b b & =| a |^2-2| a || b | +| b |^2 & =2-2 & =2(1- ) | a - b |^2 & =2 2 ^2 2 2 = & | a - b | 2 aligned