Question

Precalc question

Answer 1

Maybe I'm missing something...
but should theta be 7pi/6, not 5pi/6?

Answer 2

In number 10

Answer 3

Do you mean 11pi/6?

Answer 4

:3
yes, that's what I mean

Answer 5

I was thinking 5pi/6 was in Q3... which would make tangent positive... but it's in Q2... hmmm..

Answer 6

ok ok ok... 5pi/6 is in Q2, negative tangent, ya? :D

Answer 7

I dunno, I'm confused now :D
you're all over the place lol

Answer 8

Why did you delete your comment? D:

Lol, :]
What do you mean?

Answer 9

I think I understand now. But why would it be 5pi/6 as opposed to 11pi/6?

Answer 10

arctan(-1/sqrt3)= 11pi/6
I guess that's the confusion, ya?

arctangent can't spit out both angles, only the one in the fourth quadrant.
But it `might be` the other one that we need.

So we compare it to the location of our point.
-sqrt3+1i is located in Q2, ya?

So we don't want the angle in Q4 but in Q2 instead.
So we'll rewind our angle one full period for tangent.
11pi/6 - pi = 5pi/6

tan(5pi/6) = tan(11pi/6) = -1/sqrt3

Answer 11

Inverse tangent loses some information.
Because when you throw -1/sqrt3 into it...
it doesn't know if the two numbers were -1 and sqrt3 OR 1 and -sqrt3.

Answer 12

Ahh. That makes sense. Thanks zep.
Exactly what I was looking for!