What will the new coordinates be?

Question

A generic point P has coordinates (a,b). it is reflected over the x-axis.

Answer 1

The x-axis is horizontal, and hence when you reflect the point, it gets moved in a vertical direction. If it was initially above the x-axis, the reflection is below the x-axis. And vice versa. So only the y-component of this point changes. The new coordinates are (a,-b).