Y = Sin3x - Cos3x
y ' = (Sin3x)' - (Cos3x)' = Сos3x * (3x)' + Sin3x * (3x)' = 3Cos3x + 3Sin3x =
= 3(Cos3x + Sin3x)
Ответ 4
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Sin⁴2x + Cos⁴2x = (sin²2х+соs²2x)² - 2sin²2xcos²2x = 1 - 2sin²2xcos²2x = 1 - sin²4x
1 - sin²4x = 1/2 sin4x
2sin²4x + sin4x - 2 = 0
2t² + t - 2 = 0
t1,2 = 0,5; -1
sin4x = -1
x = 3П/8 + Пк/2
sin4x = 0,5
x = (-1)ⁿπ/12 + πк/4
-6(5-3x)=8x-7
-30+18x=8x-7
18x-8x= 30-7
10x= 23
<span><u>x=2,3</u></span>