# Vector 3ax+5ay-8az

1. Jan 12, 2006

### zekester

i have a vector h whose value is 3ax+5ay-8az where a is the unit vector in the direction beside it, how would i find the angle between this vector and the x,y,and z axes

2. Jan 12, 2006

### Gamma

Do you mean h = 3x + 5y - 8z ?

In any case, in order to find the angle between vectors, take the dot product.

Eg. Angle between h and x- axis would be given by:

h . (unit vector x) = (magnitued of h) * cos (theta)

3. Jan 12, 2006

### civil_dude

Or, you can find the sq. root of the sum of the squares (3^2+5^2+(-8)^2)^0.5

and then for each direction divide the magnitude by this value and it will give you the cos for each angle