Question

Date
proven that cos 20° cos 40 cos 60° cos 80
1/16​

Answer 1

During the sunrise the sun is set close to the Earth's horizon, and therefore light travels a longer distance through the atmosphere of the Earth.

This is the reason sun appear reddish early in the morning. The astronaut will not observe this phenomenon on the moon's surface, because the moon has no atmosphere.

Answer 2

In mathematics, the irrational numbers are all the real numbers which are not rational numbers. That is, irrational numbers cannot be expressed as the ratio of two integers. ... For example, the decimal representation of π starts with 3.14159, but no finite number of digits can represent π exactly, nor does it repeat.