The angle θ lies in Quadrant IV . sinθ=−2/3 What is cosθ?

Consider this option:
1) if the angle belongs to IV quadrant, it means cos is in [0;1];
2)  [tex]cos \alpha= \sqrt{1-sin^2 \alpha} [/tex]
using this formula cosθ=√(5/9) ⇒ cosθ=√5/3

[tex]Answer: \frac{ \sqrt{5}}{3} [/tex]