Антон
7 год назад
1-cos2x = 2sin нужно найти х
ОТВЕТЫ
Efimovich
Jul 5, 2019
1 - cos2x = 2 sinx
[ cos2a = cos^2a + sin^2a]
1 - cos^2x + sin^2x = 2sinx
sin^2x + sin^2x = 2sinx
2 sin^2x + 2 sinx = 0
2 sinx ( sinx + 1) = 0 | :2
sinx ( sinx + 1) = 0
sinx = 0
x1 = Пn, n € Z
sinx + 1 = 0
sinx = -1
x2 = -П/2 + 2Пk, k € Z
[ cos2a = cos^2a + sin^2a]
1 - cos^2x + sin^2x = 2sinx
sin^2x + sin^2x = 2sinx
2 sin^2x + 2 sinx = 0
2 sinx ( sinx + 1) = 0 | :2
sinx ( sinx + 1) = 0
sinx = 0
x1 = Пn, n € Z
sinx + 1 = 0
sinx = -1
x2 = -П/2 + 2Пk, k € Z
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