(sin 15 +cos 15)(sin 15 - cos15) = ?
Matematika
dimaseka789
Pertanyaan
(sin 15 +cos 15)(sin 15 - cos15) = ?
1 Jawaban
-
1. Jawaban ahreumlim
(a + b)(a - b)
= a² - b²
jadi
(sin 15 +cos 15)(sin 15 - cos15)
= sin²15 - cos²15
= -(cos²15 - sin²15)
= -cos(2.15)
= -cos30
= -(1/2)√3