# Why is it best to perform an orbital inclination change at apoapsis?

Wikipedia on its page on efficiency of orbital inclination change writes:

However, maximum efficiency of inclination changes are achieved at apoapsis, (or apogee), where orbital velocity V, is the lowest.

Could somebody elaborate on this statement?

To change the inclination by an angle $\alpha$, you need to apply a velocity change of $\Delta v = v \times sin \alpha$, so the higher the velocity, the higher the velocity change that you need to apply, and thus the energy that you need.