Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Vectors

Question:

Let the vectors $\vec{PQ},\vec{QR},\vec{RS},\vec{ST},\vec{TU}$ and $\vec{UP}$ represent the sides of the regular hexagon PQRSTU.

Statement-1: $\vec{PQ}×(\vec{RS} +\vec{ST})≠0$

Statement-2: $\vec{PQ}×\vec{RS} = 0$ and $\vec{PQ}×\vec{ST}≠\vec 0$

Options:

Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1. 

Statement-1 is True, Statement-2 is True; Statement-2 is not a correct explanation for Statement-1. 

Statement-1 is True, Statement-2 is False.

Statement-1 is False, Statement-2 is True.

Correct Answer:

Statement-1 is True, Statement-2 is False.

Explanation:

Clearly, $\vec{RS} +\vec{ST} =\vec{RT}$

Also, $\vec{RT}$ is not parallel to $\vec{PQ}$

$∴\vec{PQ}×\vec{RT}≠0$

So, statement-1 is true.

We observe that $\vec{PQ}$ is not parallel to $\vec{RS}$, but $\vec{PQ}$ is parallel to $\vec{ST}$.

$∴\vec{PQ}×\vec{RS}≠0$ and $\vec{PQ}×\vec{ST} = \vec 0$

So, statement-2 is not true.