f'(x)
The first derivative of a function. It's like the math version of a side-eye. You don't just look at it, you analyze it like it owes you money.
Hey, did you see that derivative? It was so fast, I thought it was going to leave calculus behind.
My teacher said I did the derivative wrong. I said, 'Sir, I did it right. You just don't like my style.'
That derivative was so good, it got a standing ovation from the entire classroom.