Предмет: Алгебра, автор: Krist698598

доказать тождество 2cos^2a-cos2a=1

Ответы

Автор ответа: daryacharikova

33

2cos^2a - cos2a = 1
2cos^2a - (2cos^2a - 1) = 1
2cos^2a - 2cos^2a + 1 = 1
1=1

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