Proving a relation between cross and dot products

[Bipolarity]

Another vector identity I have been trying to prove. My textbook lists this identity in "properties of cross products" without proving it. I have been trying to prove it, withou much luck, so some insight is appreciated.

$$u \times (v \times w) = (u \cdot w)v - (u \cdot v)w$$

Thanks!

BiP

 

[micromass]

This belongs in the homework section.