Question

The point P is reflected in x = 0 to get the point P' and the point P' is reflected in y = 0 to get the point P". Which two points out of P, P' and P" are invariant under this transformation:

Options

• P" = P

• P" = P'

• P'= P

• none of these

Answer 1

none of these

Explanation:

Let co-ordinate of P be (x, y).

We know that,

On reflection in y-axis (x = 0), the sign of x-coordinate changes.

P(x, y) = P'(−x, y)

We know that,

On reflection in x-axis (y = 0), the sign of y-coordinate changes.

P'(-x, y) = P"(−x, −y)

No two points have same co-ordinate, there are no points that are invariant.