Prove: u × (v + w) = (u × v) + (u × w)

[mk_29]

For all u, v,w, we have v × u = −(u × v) and (u + v) × w = (u × w) + (v × w).

Apply these facts to prove, without using co-ordinates, that for all vectors u, v,w, we have

u × (v + w) = (u × v) + (u × w).

I need help, do not know were to start.

Thaks

 

[Dick]

Start with ux(v+w)=-(v+w)xu. Do you see why you can do that? It's your first property.

 

[mk_29]

Start with ux(v+w)=-(v+w)xu. Do you see why you can do that? It's your first property.

Oh, ok i see what you have done. Know it should easy for me 2 prove this.

Thanks for the help