[Pip Boy]

Since the slope of a line is determined by (Change in Y)/(Change in X), it would seemingly be impossible to determine the slope of a curve at a single individual point. Using a concept introduced in Calculus, however, called a Limit, one can find trends in the Value of f(x) as X approaches a given number to kind of simulate what X would be if it could exit, such as in instances where a denominator of 0 makes f(x) impossible to actually determine. Using this concept, Derivatives are created. Using a formula derived from the slope formula, one finds what the slope of X moves towards as the Change in X gets smaller and smaller until it finally reaches 0, giving the hypothetical slope at a single point.

OR, IN ENGLISH

Since it is literally impossible to find what the slope of the tangent of X is at a single point, since you can't divide by zero, you use some DERIVATIVES and some LIMITS to find what the slope WOULD BE EQUAL TO if it WERE possible to find it; Thus accurately stating the value of the slope at X.

What the fuck Calculus. What the fuck.

EDIT: OH YE GODS MY BRAINS HOW DO YOU FIND THE AREA OF INFINITY RECTANGLES EACH WITH A WIDTH OF ZERO!?

EDIT AGAIN: I was about to Seil Tag this thread, but I think an SMB tag would be much more appropriate.