How do you find the magnitude of <-10,-5><10,5> and write it as a sum of the unit vectors?

1 Answer
Oct 23, 2017

abs( << -10, -5 >> ) = 5sqrt(5)|10,5|=55

<< -10, -5 >> = -10bb(ul hat(i)) - 5bb(ul hat(j))

Explanation:

The magnitude is given by the metric norm:

abs( << -10, -5 >> ) = sqrt((-10)^2+(-5)^2)
" " = sqrt(100+25)
" " = sqrt(125)
" " = 5sqrt(5)

And using standard unit vector bb(ul hat(i)) and bb(ul hat(j)) in the x-direction and the y-direction respectively we have:

<< -10, -5 >> = -10bb(ul hat(i)) - 5bb(ul hat(j))