Click here only if you're in doubt about this.

Points on the x-axis look like [Graphics:projectionsgr31.gif]. The distance between [Graphics:projectionsgr32.gif] and [Graphics:projectionsgr33.gif] is

[Graphics:projectionsgr5.gif][Graphics:projectionsgr34.gif]
[Graphics:projectionsgr5.gif][Graphics:projectionsgr35.gif]

This distance is as small as it can be when [Graphics:projectionsgr36.gif].
This says that [Graphics:projectionsgr37.gif] is the point on the x-axis closest to [Graphics:projectionsgr38.gif].