Question

If \( \lambda(3\hat{i} + 2\hat{j} - 6\hat{k}) \) is a unit vector, then the values of \( \lambda \) are:

• A. \( \pm \frac{1}{7} \)
• B. \( \pm 7 \)
• C. \( \pm \sqrt{43} \)
• D. \( \pm \frac{1}{\sqrt{43}} \)
• E. \( \pm \frac{1}{\sqrt{7}} \)

Hint:

Always remember that \( \lambda \) can be positive or negative because the magnitude involves an absolute value. Squaring the components of the vector first helps avoid sign errors.

Answer 1

The Correct Option is A