More Lessons for A Level Maths

Math Worksheets

A collection of videos, activities and worksheets that are suitable for A Level Maths.

What is the meaning of Var(X) and how to calculate it for a discrete random variable?

The Expected Mean E(X) In this tutorial

I show you the meaning of this function and how to use it to calculate the expected mean for a discrete random variable.

I show you what these functions mean, and how to use them.

I show you the meaning of Var(X) and how to calculate it for a discrete random variable.

I show you what these functions mean, and how to use them.

Why does Var(a)=0, Var(X ± a) = Var(X) and Var(aX) = a

Non formal proof of these results.

In this tutorial I show you the meaning of this function and how to calculate it for a discrete random variable.

Rotate to landscape screen format on a mobile phone or small tablet to use the **Mathway** widget, a free math problem solver that **answers your questions with step-by-step explanations**.

You can use the free Mathway calculator and problem solver below to practice Algebra or other math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.