tan(-120)= sqrt 3 OR - sqrt 3

Question

(Helper stated that it was sqrt 3)

But, I'm just confused over this part:

for even vs. odd functions it saids that tan(-angle) = - tan(angle)

so the even vs. odd doesn't matter since tan is positive in the QIII?

Answer 1

Tangent is an odd function. As you correctly mentioned, a test for an odd function is
if f(-x)=-f(x) for all x in the domain, then f(x) is an odd function.
Tangent fits into this category.

Since tan(120°)=-√3, tan(-120°)=√3, as Helper pointed out.

Do not forget that tan(x) has a vertical asymptote at π/2, 3π/2, ... with a period of π, while sin(x) and cos(x) have a period of 2%pi;.

Also, in case you do not already know,
an even function f(x) is such that for all x, f(x)=f(-x), example: x²=(-x)².