2sin 22,5° cos 22,5° =

Bab Trigonometri
Matematika SMA Kelas X

2 . sin 22,5° . cos 22,5°
= sin (2 . 22,5°)
= sin 45°
= 1/2 √2

2 sin A. cos A = sin 2A

2 sin 22,5° cos 22,5° = sin 2(22,5°)
                                   = sin 45°
                                   = 1/2 √2