Question

how can you determine the coordinate of a figure after a reflection over either axis?

Answer 1

This is the answer for 2-dimentional (aka, x-y axis).
If the original point is (a,b). Then
- Reflection over x-axis is (a, -b)
- Reflection over y-axis is (-a, b)

Answer 2

Locate where it is, then draw a graph to figure the exact location of it.