Tentukan nilai Sin 8π/4 x Cos 3π/4 + cos² π/6 - sin² 3π/4 = ....
fafadinawatifathin
Sin 8π/4 x cos 3π/4 + cos² π/6 - sin 3π/4 = sin 2π x cos 3π/4 + cos² π/6 - sin 3π/4 = sin 2.180 x cos 3.180/4 + cos² 180/6 - sin 3.180/4 = sin (360) x cos 135 + cos² 30 - sin 135 = (-sin 0) x (-cos 45) + cos² 30 - (sin 135) = 0 x( -1/2 √2) + 1/2 - 1/2 √2 = 1/2 - 1/2 √2 ^_^
= sin 2π x cos 3π/4 + cos² π/6 - sin 3π/4
= sin 2.180 x cos 3.180/4 + cos² 180/6 - sin 3.180/4
= sin (360) x cos 135 + cos² 30 - sin 135
= (-sin 0) x (-cos 45) + cos² 30 - (sin 135)
= 0 x( -1/2 √2) + 1/2 - 1/2 √2
= 1/2 - 1/2 √2
^_^