# Vectors help!

1. Jun 21, 2011

### draotic

1. The problem statement, all variables and given/known data
vector A,B and C are mutually perpendicular unit vectors , then |vect.A + Vect.B + Vect.C| is equal to .....???

2. Relevant equations
unit vector=vector/magnitude

3. The attempt at a solution
since they are unit vectors and are perpendicular..they obviously are lying along x , y and z axes denoted by i , j , k (caps)

2. Jun 21, 2011

### AJKing

Are we sure that this is a 3 dimensional incident?

Edit: I just realized, I clicked on "Advanced Physics" . . . gonna go back to the Introductory forum now.

Good luck :).

3. Jun 21, 2011

### SteamKing

Staff Emeritus
Three unit vectors can be mutually perpendicular, but it is not necessary for the three vectors to coincide, or lie along, the coordinate axes.

Remember, if two arbitrary vectors A and B are defined such that A dot B = 0, then A and B are perpendicular. If we form the cross product such that C = A cross B, then the vectors A, B, and C will be mutually perpendicular.

The magnitude is given by the standard Euclidean norm Sqrt(A^2 + B^2 + C^2).