Bantu jawab sama caranya
[tex] \frac{ \sin(75°) - \sin(15°) }{ \cos(105°) + \cos(15°) } [/tex]
[tex] = \frac{2 \cos(45°) \sin(30°) }{2 \cos(60°) \cos(45°) } [/tex]
[tex] = \frac{ \sin(90° - 60°) }{ \cos(60°) } [/tex]
[tex] = \frac{ \cos(60°) }{ \cos(60°) } [/tex]
[tex] = 1[/tex]
Penjelasan dengan langkah-langkah:
sin 75° – sin 15°
cos 105° + cos 15°
2 cos (75+15)°/2 sin (75–15)°/2
= ------------------------------------------
2 cos (105+15)°/2 cos (105–15)°/2
2 cos 90°/2 sin 60°/2
= -------------------------------
2 cos 120°/2 cos 90°/2
2 cos 45° sin 30°
= -------------------------
2 cos 60° cos 45°
½√2 x ½
= -----------------
½ x ½√2
= ½/½ x ½√2/½√2
