Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Vectors

Question:

If $|\vec a| = 10, |\vec b| = 2$ and $\vec a . \vec b = 12$, then value of $|\vec a×\vec b|$ is:

Options:

5

10

14

16

Correct Answer:

16

Explanation:

The correct answer is Option (4) → 16

Given: $|\vec{a}| = 10$, $|\vec{b}| = 2$, $\vec{a} \cdot \vec{b} = 12$

Use formula: $|\vec{a} \times \vec{b}| = \sqrt{|\vec{a}|^2 |\vec{b}|^2 - (\vec{a} \cdot \vec{b})^2}$

$|\vec{a} \times \vec{b}| = \sqrt{10^2 * 2^2 - 12^2} = \sqrt{400 - 144} = \sqrt{256} = 16$

Answer: $16$