Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
If the vectors $\mathbf{i}-2 x \mathbf{j}-3 y \mathbf{k}$ and $\mathbf{i}+3 x \mathbf{j}+2 y \mathbf{k}$ are orthogonal to each other, then the locus of the point $(x, y)$ is
MathematicsVector AlgebraTS EAMCETTS EAMCET 2011
Options:
  • A a circle
  • B an ellipse
  • C a parabola
  • D a straight line
Solution:
2516 Upvotes Verified Answer
The correct answer is: a circle
Since, vectors are orthogonal.
$\begin{aligned}
& \therefore \quad(\mathbf{i}-2 x \mathbf{j}-3 y \mathbf{k}) \cdot(\mathbf{i}+3 x \mathbf{j}+2 y \mathbf{k})=0 \\
& \Rightarrow \quad 1-6 x^2-6 y^2=0 \Rightarrow x^2+y^2=\frac{1}{6}
\end{aligned}$
Hence, the locus of a point is a circle.

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.