The problem that I am unsure about is: k x (i - 2j). What are the rules for adding and subtracting vectors like this?

Printable View

- Sep 19th 2013, 03:25 PMShadow236Vectors and properties of cross products
The problem that I am unsure about is: k x (i - 2j). What are the rules for adding and subtracting vectors like this?

- Sep 19th 2013, 04:06 PMPlatoRe: Vectors and properties of cross products
Be careful about notation, in particular capitalization.

I think you mean: $\displaystyle k\times(i-2j)~?$

The rules are: $\displaystyle \vec{a}\times(\vec{b}+\vec{c})=(\vec{a}\times\vec{ b})+(\vec{a}\times\vec{c})$ and $\displaystyle (\alpha\vec{ a}\times\vec{b})=\alpha(\vec{a}\times\vec{b})$ - Sep 19th 2013, 04:09 PMShadow236Re: Vectors and properties of cross products
Okay, I fixed it.

In that case I went through the problem like this...

= k x i + (-2)(k x j)

= j - 2i