Reflection in the line y=−x :

The rule for a reflection in the origin is (x,y)→(−y,−x) .

What is the notation for reflection Y =- X?

Solution: This is a reflection across the line y− = −x. The notation is ry=−x(x,y) → (−y,−x).

What is the rule for the reflection?

The rule of reflection is very simple and logical. It says that when a point (x,y) is reflected along the x-axis, the y- coordinate becomes negative and when the same point is reflected along the y- axis, the x coordinate becomes negative.