Question

which of the following vectors has a direction of 311?
a) <7, -7 square root3>
b) <2, -5>
c) <2 square root 3, -4>
d) <-1, square root 3>
e) none of these

Answer 1

plzz help

Answer 2

Direction can be found using

\[\large \tan^{-1}(\frac{y}{x})\]

Answer 3

how can we find 311 then?

Answer 4

Well if we know that

\[\large \theta = \tan^{-1}(\frac{y}{x})\]

We know that \(\large \theta = 311\) so we just need to see which coordinates will make our equation = 311

So for example the first choice you have there...x = 7 and y = -7√3 so plug those in...and see if it comes out to 311

Answer 5

thanks it helps a lot