# Finding a vector with given properties

1. Dec 11, 2011

### alexf322

So I need to find a vector v with these properties
1. magnitude of 10
2. angle of 45° with positive x-axis
3. angle of 75° with positive y-axis
4. positive k component.

I understand basically just that the k component has to be positive.
Any help would be appreciated.

2. Dec 11, 2011

### SammyS

Staff Emeritus
Use the following scalar products (dot products).

$\vec{v}\cdot \hat{i}$

$\vec{v}\cdot \hat{j}$

In general, $\vec{A}\cdot\vec{B}=\left|\vec{A}\right|\left|\vec{B}\right|\cos(\theta)$