COMEDK · Maths · 33. Vector Algebra
If the vectors \(\mathbf{a}=2 \hat{\mathbf{i}}-3 \hat{\mathbf{j}}+4 \hat{\mathbf{k}}, \mathbf{b}=\hat{\mathbf{i}}+2 \hat{\mathbf{j}}-\hat{\mathbf{k}}\) and \(\mathbf{c}=m \hat{\mathbf{i}}-\hat{\mathbf{j}}+2 \hat{\mathbf{k}}\) are coplanar, then the value of \(m\) is
- A \(\frac{5}{8}\)
- B \(\frac{8}{5}\)
- C \(\frac{-7}{4}\)
- D \(\frac{2}{3}\)
Answer & Solution
Correct Answer
(B) \(\frac{8}{5}\)
Step-by-step Solution
Detailed explanation
Since, vectors a, b and c are coplanar \(\therefore[\mathbf{a} b \mathbf{c}]=0 \Rightarrow \mathbf{a} \cdot(\mathbf{b} \times \mathbf{c})=0\) Now,…
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