The cumulative distribution function is a monotonically increasing function.

The function is called the probability density function of the random variable .

If , then and are independent.

For and one has .

The integral of a scalar field on the parametrized surface is:

A vector field is conservative if for any closed curves the line integral is zero.

If a differentiable function has a local minimum or local maximum at , then for any direction the directional derivative of at is zero.

In a vector sequence is convergent if and only if all its coordinate sequences are convergent.

In an orthonormal system the vectors are all unit vectors.

The triangle inequality is .