Calclulations Not So Easy

You r not a calculation,
But an algebraic expression.
This can’t be differentiation,
Either I would have it an integration.

There is nothing to be added,
But a little subtraction ,
Then with some multiplication,
Divide it through the whole calculation.

You are a continuous function
Which can’t be solved by normal calculation,
But have a tricky solution.

If I would have got a chance to solve
I would have done a square of you,
Then added three along with you,
So that I get a whole of you.

Does u know who u r?

Are solve it then you’ll know.