Why is the definite integral numerically equal to the area of ​​the figure under the graph?

Question

Mathematics

How to prove it?
Why does it turn out that the antiderivative is equal to the area, how to come to this algebraically?

Answer 1

The antiderivative is not equal to the area, it is also a function-qi-I.
Algebraically, there is no way to come to this, it is considered and proved in matan.
Answer to the title question: because .
PS Well, what else do you have there? Why does the Volga flow into the Caspian Sea ? SchA, I remember why - I'll write.

Answer 2

Recently, in an intelligence questioning , they talked about this (the subject is physics).