*Kiddle Encyclopedia.*

# Cross product facts for kids

The **cross product** is a mathematical operation which can be done between two vectors. After performing the Cross Product, a new vector is formed. The cross product of two vectors is **always** perpendicular to **both** of the vectors which were "crossed". This means that the cross product must always be used in 3-Dimensional space.

## Contents

## Importance of the cross product

Being a vector operation, the Cross Product is extremely important in all sorts of sciences (particularly physics), engineering, and mathematics. One important example of the Cross Product is in torque or moment.

## How to perform the cross product

Like any mathematical operation, the Cross Product can be done in a straightforward way.

### Two dimensions

If

and

then

or

and

is just a symbol which says that our new vector is pointing up (in the z-direction). If you "cross" two vectors which are both in the x-y plane, the product will **always** be perpendicular to **both** vectors, and if both vectors are in the x-y plane, the only way for it to be perpendicular to both is to be in the z direction. If the value of is positive, then it points OUT of the page; if its value is negative, then it points INTO the page.

### Three dimensions

If

and

then