jika sin x - cos x = 1/4.maka nilai 8 sin x . Cos x adalah......tolong ya sama caranya...gk boleh asal asalan

Fungsi Trigonometri

sin x - cos x = 1/4
(sin x - cos x)² = (1/4)²
sin² x - 2 sin x cos x + cos² x  = 1/16
(sin² x+ cos ² x) - 2 sin x cos x = 1/16
1 - 2 sin x cos x = 1/16
2 sin x cos x = 1 -1/16  = 15/16
sin x cos x = 15/32

nilai 8 sin x  cos x  =  8 (15/32)
8 sin x cos x  = 15/4