The function has a limit at if and only if all its coordinate functions have a limit at .

In the norm is defined as :

If in a system the vectors are orthogonal to each other, then it is an orthonormal system.

For the distance function one has .

If is a linear map, then .

Let be an event and denotes the relative frequency of during independent experiment. Then

The cumulative density function of the exponential distribution is

• , if
• , if

The hypergeometric distribution with parameters and is the discrete probability distribution with possible values and probabilities

The standard deviation of the random variable is

Let be a continuous random variable with probability density function . Then the expected value of is