Question

A vector perpendicular to both of the vectors $i + j + k$ and $i + j$ is

• A. i + j
• B. i – j
• C. $c(i - j)$, c is a scalar
• D. None of these

Answer 1

Answer: (C)

$c(i - j)$, c is a scalar

Answer 2

Vector perpendicular to both of the vectors $i + j + k$ and $i + j$ is,$\frac{(i + j + k) \times (i + j)}{|(i + j + k) \times (i + j)|}$ $= \frac{- i + j}{\sqrt{2}} = \frac{- 1}{\sqrt{2}}(i - j)$ or $c(i - j),$ where c is a scalar.