# How do you find the angle between the vectors #u=<1,0># and #v=<0,-2>#?

##### 2 Answers

Please see the explanation.

#### Explanation:

Two methods to dot-product to compute the dot product are:

Where

where the magnitudes are

To do this problem, you compute the dot-product using method [1]:

This is a special case where the dot-product is zero and we instantly know that

Next, compute the magnitudes:

Into the equation for method [2], substitute 0 for

Solve the equation for

This is the answer.

#### Explanation:

The dot ( scalar ) product

So, the cosine of the angle,

In

from