Question

In what situation do we need to use Substitution Rule? What is the purpose for using Substitution Rule?

Answer 1

Answer:

Substitution rule is one of the most important rule to solve the integrals problem.

In substitution rule we substitute  different  variable in such a way that it can simplify the question.

example: when we have to solve "Sin x²" we cannot solve it but

               if question is "x  Sin x²" we can substitute x² with t and can solve it.

The purpose of substitution rule is to simplify the problem of integrals.