# Are the vectors #u=<1, -2># and #v=<4, 8># parallel, orthogonal, or neither?

##### 1 Answer

Neither parallel nor orthogonal. The angle between the two vectors is:

#### Explanation:

Given:

Compute the dot-product:

We computed the dot-product by multiplying the respective components of the vectors. Another definition of the dot-product is the magnitudes of the vectors multiplied by the angle between them:

Compute the magnitudes of the two vectors:

Substitute the values for the dot-product and the magnitudes into equation [1]: