How do I do subtract these vectors?

Question

l(5i - 3j) - (-i + 4j)l

I think the absolute value is messing me up.

Answer 1

You subtract the i and j parts separately.

5i - (-i) = 6i

(-3j) - (+4j) = -7j

So overall you get:     6i - 7j

Then because they are between these lines: I(5i - 3j)...+4j)I    It means that you have to find the modulus or magnitude of the vectors and you just use pythagorus for that:

so square root ( 6^2 + (-7)^2) and you get 9.22 to 3 s.f

I hope that helps!!