( - 0,2p - 10q)^2 =
= ( - 0,2p)^2 - 2( - 0.2p)*10q + 100q^2 =
= 0,04p^2 + 4pq + 100q^2
SinA-Sin3A 1/2 - 3*(1/2) 1/2 - 3/2 -2/2
--------------- = ---------------- = ------------- = -------- = -0,5 - Решение
Sin4A 4*(1/2) 4/2 4/2
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sinA = 1/2
(5x - 1)^2 - 16x^2 = 0
(5x - 1 - 4x)(5x - 1 + 4x) = 0
(x - 1)(9x - 1) = 0
x - 1 = 0
x = 1
9x - 1 = 0
9x = 1
x = 1/9
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x^2 + 6x + 9 + x^2 - 8x + 16 = 2(4x + 12 - x^2 - 3x)
2x^2 - 2x + 25 = 2(x + 12 - x^2)
2x^2 - 2x + 25 = 2x + 24 - 2x^2
4x^2 - 4x + 1 = 0
(2x - 1)^2 = 0
2x - 1 = 0
2x = 1
x = 1/2 = 0,5