Tan x=4/3. Write down possible value of cos x.?

3,4,5 right triangle
4/3 = (4/5) / (3/5)
top is sine, bottom cosine, since tan = sin/cos
so answer is 3/5 if x is in QI and -3/5 if x is in QIII

±3/5

cos x = 3 / 5

cos(x) = ±√1/(tan(x)^2 +1) = ±√(1/(16/9 +1)
.. = ±√(9/25)
cos(x) = ±3/5

±⅗
(cosθ,sinθ) = (⅗,⅘), (-⅗,-⅘)

Tan x = Sin x / Cos x = 4/3

Since Sin^2 x + Cos^2 x = 1, you can use that to find that Sin x = +/- 4/5 and the Cos x = +/- 3/5

± 3 / 5