Question

Tolong, butuh jawaban cepat. himpunan penyelesaian 2 cos x -sec x=1

Answer 1

2 cos x - 1/ cos x = 1
2 cos x - 1/cos x - 1 =0
kalikan cos x
2 cos² x - cos x - 1 = 0
(2 cos x +1)(cos x -1) 0
cos x = -1/2 atau cos x = 1