tentukan cos 15 tolong sekali lagi kak andilufpi

cos 15 = cos (45 - 30)

= cos 45 . cos 30 + sin 45 . sin 30

= akar 2 / 2 . akar 3 / 2 + akar 2 / 2 . 1/2

= akar 6 / 4 + akar 2 / 4
= (akar 6 + akar 2) / 4

langsung aja y

cos 15 = cos (45-30)

= cos 45 cos 30 + sin 45 sin 30

= ½√2 . ½√3 + ½√2 . ½

= ¼√6 + ¼√2

= ¼ (√6 + √2)

semoga berguna +_+