L Hospital's Rule
limx→4x2−16x−4limx→∞4x2−5x1−3x2In the first limit if we plugged in x=4 we would get 0/0 and in the second limit if we “plugged” in infinity we would get ∞/−∞ (recall that a...
Differentials:
In calculus, the differential represents the principal part of the change in a function y = f(x) with respect to changes in the independent variable. The differential dy is defined by
where is the derivative of f with respect to x, and dx is an additional real variable (so that dy is a function of x and dx). The notation is such that the equation
holds, where the derivative is represented in the Leibniz notation dy/dx, and this is consistent with regarding the derivative as the quotient of the differentials. One also writes

Tangents and Normal:

Equation of Tangent and Normal:

The angle of intersection of two curves:
