Answer:
x =
, x =

Explanation:
using the trigonometric identity
• sec x =

isolate sec x by subtracting 6 from both sides and dividing both sides by 2
2sec x = - 4 ⇒ sec x = - 2, hence
= - 2
⇔ cosx = -

since cos x < 0 then x is in second/ third quadrant
x =
or x =
