Medium MCQ +4 / -1 PYQ · JEE Mains 2025

Let $A, B, C$ be three points in xy-plane, whose position vector are given by $\sqrt{3} \hat{i}+\hat{j}, \hat{i}+\sqrt{3} \hat{j}$ and $a \hat{i}+(1-a) \hat{j}$ respectively with respect to the origin O . If the distance of the point C from the line bisecting the angle between the vectors $\overrightarrow{\mathrm{OA}}$ and $\overrightarrow{\mathrm{OB}}$ is $\frac{9}{\sqrt{2}}$, then the sum of all the possible values of $a$ is :

  1. A <p>2</p>
  2. B <p>0</p>
  3. C <p>$ \frac{9}{2} $</p>
  4. D <p>1</p> Correct answer

Solution

<p>$$\begin{aligned} &\text { Equation of angle bisector : } \mathrm{x}-\mathrm{y}=0\\ &\begin{aligned} & \left|\frac{\mathrm{a}(1-\mathrm{a})}{\sqrt{2}}\right|=\frac{9}{\sqrt{2}} \Rightarrow \mathrm{a}=5 \text { or }-4 \\ & \text { Sum }=5+(-4)=1 \end{aligned} \end{aligned}$$</p>

About this question

Subject: Mathematics · Chapter: Vector Algebra · Topic: Types of Vectors

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