InterviewSolution
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InterviewSolution
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For tow vectros ` vec A` and `vec B` ` | vec A + vec B| = | vec A- vec B|` is always true when.A. `|A|=|B|!= 0`B. `A_|_B`C. `|A|=|B|!= 0` and A and B are parallel or anti-parallelD. when either |A| or |B| is zero |
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Answer» Correct Answer - B::D Given, |A+B|=|A-B| `rArr " " sqrt(|A|^(2)+|B|^(2)+2|A||B| cos theta)=sqrt(|A|^(2)+|B|^(2)-2|A||B|cos theta)` `rArr " " |A|^(2)+|B|^(2)+2|A||B|cos theta = |A|^(2)+|B|^(2)-2|A||B|cos theta` `rArr " " 4|A||B| cos theta =0` `rArr " " |A||B|cos theta=0` `rArr " " |A|=0 or |B| = 0 or cos theta =0` `rArr " " theta=90^(@)` When `theta=90^(@)`, we can say that `A_|_B` |
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