Vector Algebra Question - CBSE

Question

If $|\vec{a}| = 3, |\vec{b}| = 4$, then the value of $\lambda$ for which $\vec{a} + \lambda \vec{b}$ is perpendicular to $\vec{a} - \lambda \vec{b}$ is:
(a) $\pm \dfrac{3}{4}$
(b) $\pm \dfrac{4}{3}$
(c) $\pm \dfrac{9}{16}$
(d) $\pm \dfrac{16}{9}$

Accepted Answer

9 - 16\lambda^2 = 0 \Rightarrow \lambda = \pm 3/4. [1.0 Mark]

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🎯 Official CBSE Marking Scheme:
Evaluating $\lambda = \pm 3/4$: 1.0 Mark

Question:

Step-by-Step Solution

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