I'm learning calculus, but I'm still a beginner on that. So the concepts I actually have are the following: The derivative is the slope of the line tangent to the curve of a function at a given point (so we need 1 argument: the x you want the slope). The integral is the area under the curve of a function between two given points (so we need 2 arguments: the start and the end). So, considering my concepts are right, continue reading. I know too that integral and derivative are inverse operations of calculus (like multiplication and division). But I can't really understand how can the slope of a tangent line to the curve be the inverse of the area under the curve. And I can't even understand how these two operations are comparable this way because the first one needs one argument and the second one needs two arguments. Someone please help me understanding this... Thanks in advance.