Question

If \[ \vec{a}=2\hat{i}-\hat{j}+3\hat{k} \] and \[ \vec{b}=\hat{i}+4\hat{j}-2\hat{k}, \] then \(\vec{a}\cdot\vec{b}\) is equal to:

• A. \(8\)
• B. \(-8\)
• C. \(4\)
• D. \(-4\)

Hint:

For dot product: \[ \vec a\cdot\vec b = a_1b_1+a_2b_2+a_3b_3 \] Multiply corresponding components carefully and watch the signs.

Answer 1

The Correct Option is B