cos 5п/9 cos 13п/9 - sin 5п/9 sin 13п/9=. Created by ЛюблюСоссию. algebra-ru

9=...

July 2022 1 5 Report

cos 5п/9 cos 13п/9 - sin 5п/9 sin 13п/9=

nKrynka Решение
Cos 5п/9 cos 13п/9 - sin 5п/9 sin 13п/9= cos(5π/9 + 13π/9) =
cos(18π/9) = cos2π = 1

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