JEE Main2012MathematicsComplex NumberActual
|z₁+z₂ |^2+ |z₁-z₂ |^2 is equal to
Options
- A2 ( |z₁ |+ |z₂ | .
- B2 ( |z₁ |^2+ |z₂ |^2 )
- C|z₁ | |z₂ |
- D|z₁ |^2+ |z₂ |^2
Correct answer
B. 2 ( |z₁ |^2+ |z₂ |^2 )
Step-by-step solution
|z₁+z₂ |^2+ |z₁-z₂ |^2 = |z₁ |^2+ |z₂ |^2+2 |z₁ | |z₂ |+ |z₁ |^2+ |z₂ |^2-2 |z₁ | |z₂ | =2 |z₁ |^2+2 |z₂ |^2=2 [ |z₁ |^2+ |z₂ |^2 ]