If sec4x - sec2x = 2, Find cos^2(x)?

Question

If sec4x - sec2x = 2, Find cos^2(x) [0 <= x <= π/2]

Answer 1

Going to take a guess that you mean:-
sec^(4) x - sec ² x - 2 = 0
(sec ² x - 2) (sec ² x + 1) = 0
sec ² x = 2 , sec ² x = - 1
cos ² x = 1/2 , cos ² x = - 1
Accept cos ² x = 1/2
(Question asks that cos ² x be found)