JEE Mains · Maths · STD 12 - 10. vector algebra
Let \(\overrightarrow{ c }\) be a vector perpendicular to the vectors \(\overrightarrow{ a }=\hat{ i }+\hat{ j }-\hat{ k }\) and \(\overrightarrow{ b }=\hat{ i }+2 \hat{ j }+\hat{ k }.\) If \(\overrightarrow{ c } \cdot(\hat{ i }+\hat{ j }+3 \hat{ k })=8\) then the value of \(\overrightarrow{ c } \cdot(\overrightarrow{ a } \times \overrightarrow{ b })\) is equal to ...... .
- A \(24\)
- B \(28\)
- C \(36\)
- D \(39\)
Answer & Solution
Correct Answer
(B) \(28\)
Step-by-step Solution
Detailed explanation
\(\overrightarrow{ c }=\lambda(\overrightarrow{ a } \times \overrightarrow{ b })\) \(\overrightarrow{ a } \times \overrightarrow{ b }=\left|\begin{array}{ccc}\hat{ i } & \hat{ j } & \hat{ k } \\ 1 & 1 & -1 \\ 1 & 2 & 1\end{array}\right|\)…
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