Titlace: Why is people in the mirror to reverse, but didn't reverse it?
Solution: The human is the z-axis, the upper is positive; the left and right is the X-axis, the right is the positive direction; the front and then the Y axis, the front direction is forward. Since the mirror plane is perpendicular to the XY plane, and parallel to the X-axis, in the opposite direction of the mirror coordinate system, Y, the positive direction of the Z-axis and the X-axis does not change, so the upper and lower mirrors No reverse.
The X direction of the mirror did not change, only the Y-axis positive direction changed. In order to prove this, let's make a trial, when you turn your hands forward, the hands of the mirror is relative to you, and when you pull the hand left straight, the mirror people are also straight.
So, why do you understand people in mirrors and your left and right? That's because you think that the front and rear direction of the mirror is coming, although this is not true, the average person will think so. The consequence of this is actually a 180 degree in the mirror around the Z-axis, then, the left hand of the mirror will naturally become your right hand.
