Question

Find length and direction of u
u = <-4 (sqrt3),4>

Answer 1

The initial point is (0,0)

Answer 2

@jim_thompson5910 :)

Answer 3

u = <a,b>

length of u = |u| = sqrt(a^2+b^2)

this is the same as saying "the magnitude of vector u"

Answer 4

direction:

theta = arctan(b/a)

if theta is negative, and you know for a fact that the vector is in Q2, then add on 180 degrees

Answer 5

oh, I didn't make that connection! ok.

Answer 6

and I didn't know that about direction at all xD thanks :)
let me get the answers real quick.

Answer 7

Length = 8 ?

Answer 8

Direction = 178.95

Answer 9

I agree with the length, but not the direction

Answer 10

b/a = 4/(-4*sqrt(3)) = -0.57735026918962

arctan(b/a) = arctan(-0.57735026918962) = -29.9999999999998
which is essentially -30

add on 180
-30+180 = 150

Answer 11

hrm
when I do
= arctan (4/(-4 sqrt3)) it comes out to = -0.52

Answer 12

you must be in radian mode

Answer 13

...oh xD

Answer 14

Yeah you're right, I was.

Answer 15

if you're using desmos, then click the wrench to change to degree mode

Answer 16

Scientific calculator :) thanks though, I use desmos as well.