COMEDK · Maths · 33. Vector Algebra
If \(\mathbf{p}=\hat{\mathbf{i}}+\hat{\mathbf{j}}, \mathbf{q}=4 \hat{\mathbf{k}}-\hat{\mathbf{j}}\) and \(\mathbf{r}=\hat{\mathbf{i}}+\hat{\mathbf{k}}\), then the unit vector in tile direction of \(3 p+q-2 r\) is
- A \(\hat{\mathbf{i}}+2 \hat{\mathbf{j}}+2 \hat{\mathbf{k}}\)
- B \(\frac{1}{3}(\hat{\mathbf{i}}-2 \hat{\mathbf{j}}+2 \hat{\mathbf{k}})\)
- C \(\frac{1}{3}(\hat{\mathbf{i}}-2 \hat{\mathbf{j}}-2 \hat{\mathbf{k}})\)
- D \(\frac{1}{3}(\hat{\mathbf{i}}+2 \hat{\mathbf{j}}+2 \hat{\mathbf{k}})\)
Answer & Solution
Correct Answer
(D) \(\frac{1}{3}(\hat{\mathbf{i}}+2 \hat{\mathbf{j}}+2 \hat{\mathbf{k}})\)
Step-by-step Solution
Detailed explanation
We have, \(\mathbf{p}=\hat{\mathbf{i}}+\hat{\mathbf{j}}, \mathbf{q}=4 \hat{\mathbf{k}}-\hat{\mathbf{j}}\) and \(\mathbf{r}=\hat{\mathbf{i}}+\hat{\mathbf{k}}\)…
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