Question:medium
A unit vector $\vec{b}$ is coplanar with $\hat{i} + \hat{j} + 2\hat{k}$ and $\hat{i} + 2\hat{j} + \hat{k}$ and is perpendicular to $\hat{i} + \hat{j} + \hat{k}$. Then $\vec{b} \cdot \hat{i}$ equals
A unit vector $\vec{b}$ is coplanar with $\hat{i} + \hat{j} + 2\hat{k}$ and $\hat{i} + 2\hat{j} + \hat{k}$ and is perpendicular to $\hat{i} + \hat{j} + \hat{k}$. Then $\vec{b} \cdot \hat{i}$ equals
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Perpendicular condition simplifies equations dramatically—use it early.
Updated On: Apr 30, 2026
- $0$
- $1$
- $\frac{3}{2}$
- $2$
- $4$
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The Correct Option is A
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