7/7;14/7;21/7;28/7;35/7;42/7;49/7
5/5;10/5;15/5;20/5;25/5;30/5;35/5
4/4;8/4;12/4;16/4;20/4;24/4;28/4
4(1 - Cos²x) - Cosx -1 = 0
4 - 4Cos²x - Cosx -1 = 0
4Cos²x + Cosx -3 = 0
Cosx = t
4t² + t - 3 = 0
D = 49
a) t₁ = (-1+7)/8 = 6/8 = 3/4 б) t₂ = (-1 - 7)/8 = -1
Cosx = 3/4 Сos x = -1
x = +-arcCos(3/4) + 2πk , k ∈Z x = π + 2πn , n ∈ Z
bₙ = 17,5 * (-2)ⁿ b₇ = ?
b₇ = 17,5 * (- 2)⁷ = 17,5 * (- 128) = - 2240
Ответ:
Объяснение:
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A1= -3*1+1= -2
a3= -3*3+1= -8
a10= -3*10+1= -29