Thread: why this doesn't work, cross product.

1. why this doesn't work, cross product.

need to explain why these are not valid, or meaningless.

1. a x (b*c)

2. (a*b) x c

3. (a*b) x (c*d)

not sure whats wrong with each of them, thankyou for any help.

2. Recall that the dot product between two vectors gives you a number.

Also recall that the cross product is defined between two vectors, not numbers.

Can you see what's wrong with your expressions?

3. okay, so each of those have a problem because two vectors multiplied will give a number.

and then its a number x a vector, which can't happen for the cross product which looks like the case for each of them,

correct?