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The angle between the line \(\bar{r} = (\hat{i} + 2\hat{j} + \hat{k}) + \lambda(\hat{i} + \hat{j} + \hat{k})\) and the plane \(\bar{r}\cdot(2\hat{i} - \hat{j} + \hat{k}) = 8\) is _____.

Q.1 (iv) The angle between the line \(\bar{r} = (\hat{i} + 2\hat{j} + \hat{k}) + \lambda(\hat{i} + \hat{j} + \hat{k})\) and the plane \(\bar{r}\cdot(2\hat{i} - \hat{j} + \hat{k}) = 8\) is _____.

A. \(\sin^{-1}\left(\dfrac{\sqrt{2}}{3}\right)\)

B. \(\sin^{-1}\left(\dfrac{\sqrt{3}}{2}\right)\)

C. \(\sin^{-1}\left(\dfrac{1}{2}\right)\)

D. \(\sin^{-1}\left(\dfrac{1}{\sqrt{2}}\right)\)

1 answer

Best answer

Answer: A. \(\sin^{-1}\left(\dfrac{\sqrt{2}}{3}\right)\)

Answer: (a) \(\sin^{-1}\left(\dfrac{\sqrt{2}}{3}\right)\)

\(\bar{b} = \hat{i} + \hat{j} + \hat{k}\), \(\bar{n} = 2\hat{i} - \hat{j} + \hat{k}\). \(\sin\theta = \dfrac{|\bar{b}\cdot\bar{n}|}{|\bar{b}||\bar{n}|} = \dfrac{2 - 1 + 1}{\sqrt{3}\sqrt{6}} = \dfrac{2}{3\sqrt{2}} = \dfrac{\sqrt{2}}{3}\).

Doubtly AI · 28 Oct 2026 AI-verified · Oct 2026 Report
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