**I was given: a=2i - 3j - k, b=2i - j and c = -3j + k** **(a) Find a + b, |a + b| Which I'm sure I'm correct with)**

a + b = 4i - 2j - k
|a + b| = *33 (* representing a square root)

**(b) Find the unit vector in the direction a-c** (I'm more confused about this guestion)

Here I found -(a+c), assuming it would be interpreted in the direction c towards a ??

That is a + c = 2i - 2k

I found unit vector then to be: - 4/*40 (2i - 6j)

And therefore unit vector a-c: 4/*40 (-2i + 6j)

I'm confused, because if I did it a-c I'd get 0/*8

thanks for any help