Question

Ιf tan(Θ) = 2 , 180* < Θ < 270* whats the value of cos(Θ) ?

Answer 1

do you know the meaning of this :
180* < Θ < 270*
in which quadrant Θ lies ?

Answer 2

Yea its the third

Answer 3

in 3rd quadrant , cos is positive or negative ?

Answer 4

negative

Answer 5

good, remember this.
so, you have tan(Θ) = 2
use, \(\sec^2 x =1+\tan^2x\)
and find sec first.

Answer 6

and then sec = 1/cos :P thanks!!

Answer 7

yes :)
welcome ^_^