Question

The image of the point with position vector \[ \mathbf{i} + 3 \mathbf{k} \] in the plane \( \mathbf{r} \cdot (\mathbf{i} + \mathbf{j} + \mathbf{k}) = 1 \) is:

• A. \( \mathbf{i} - 2\mathbf{j} + \mathbf{k} \)
• B. \( \mathbf{i} + 2\mathbf{j} - \mathbf{k} \)
• C. \( -\mathbf{i} - 2\mathbf{j} + \mathbf{k} \)
• D. None of these

Hint:

When finding the image of a point across a plane, use the reflection formula to obtain the coordinates of the reflected point.

Answer 1

The Correct Option is C