What is the relationship between altitude and atmospheric pressure and boiling point?

What is the relationship between altitude and atmospheric pressure and boiling point?

Formula P=p (density) g (acceleration of gravity) h (height)
The altitude is high, the atmosphere is thin, the air pressure is low, the air pressure is low, the boiling point is low. The water of Qinghai-Tibet Plateau is hard to burn, this is the truth

Relation between boiling point and air pressure

First of all, it should be a physical problem.
The higher the pressure, the higher the boiling point.
This principle can be shown in the life, the normal water temperature boiled water 100 degrees, is the boiling point to the boiling point, the water temperature is not to go, but with the high pressure pot can increase the boiling point, the water temperature can be increased, so easy to cook meat and so on.
Another, to the very high altitude, such as China's Qinghai-Tibet Plateau, the air is thinner, low pressure, where the water less than 90 degrees, open, cooking things is very difficult to cook.