Sin105°cos105°adalah
Matematika
Hestiimutz
Pertanyaan
Sin105°cos105°adalah
1 Jawaban
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1. Jawaban whongaliem
gunakan rumus : 2 .sin α . cos α = sin 2α
sin α . cos α = (1/2) .sin 2α
sin 105° . cos 105° = (1/2).sin (2 .105°)
= (1/2).sin 210°
= (1/2).sin (180° + 30°)
= (1/2). - sin 30°
= (1/2) (- 1/2)
= - 1/4