Thread: Vector Property

Show that A.(B+C)=A.B+A.C using anything but the coordinate definition of the dot product.

Any ideas?

Thanks

Originally Posted by billa

Show that A.(B+C)=A.B+A.C using anything but the coordinate definition of the dot product.

Any ideas?

Thanks

$\displaystyle A.(B+C) = |A||(B+C)|cos(\theta) $

Use that definition.

I tried to use that, but couldn't. I know I need to show that

|A||B+C|cos(theta)=|A||B|cos(a1)+|A||C|cos(a2)

but I can't come up with any relationships between the angles (or anything else for that matter).