How axiom is used in a sentence for proving? How axioms must be remembered
Euclids geometry chapter is not given
You can’t prove something using nothing. You need at least a few building blocks to start with, and these are called Axioms.
Mathematicians assume that axioms are true without being able to prove them. However this is not as problematic as it may seem, because axioms are either definitions or clearly obvious, and there are only very few axioms. For example, an axiom could be that a + b = b + a for any two numbers a and b.
Axioms are important to get right, because all of mathematics rests on them. If there are too few axioms, you can prove very little and mathematics would not be very interesting. If there are too many axioms, you can prove almost anything, and mathematics would also not be interesting. You also can’t have axioms contradicting each other.
Mathematics is not about choosing the right set of axioms, but about developing a framework from these starting points. If you start with different axioms, you will get a different kind of mathematics, but the logical arguments will be the same. Every area of mathematics has its own set of basic axioms.
When mathematicians have proven a theorem, they publish it for other mathematicians to check. Sometimes they find a mistake in the logical argument, and sometimes a mistake is not found until many years later. However, in principle, it is always possible to break a proof down into the basic axioms.