Question 1040563
*[tex \large \tan(x+y) = \frac{\tan x + \tan y}{1 - \tan x \tan y}]


To find *[tex \large \tan x], use the fact that *[tex \large \sin^2 x + \cos^2 x = 1] for all angles x (Pythagorean thm.). You already know *[tex \large \cos x = -\frac{1}{3}] so you can determine sin x (note: angle x is in quadrant 3, so sin x is negative).


Do the same thing for determining cos y.


Once you have found these two values, you have enough information to determine tan x and tan y, and tan (x+y).