Ответ:
Пошаговое объяснение:
sin2x-sin8x = 2*(-sin3x)* cos5x
2*(-sin3x)* cos5x - cos^2 (5x) + sin^2 (5x) - sin^2 (5x) - cos^2 (5x) = 0
2*(-sin3x)* cos5x - 2cos^2 (5x) = 0
sin3x * cos5x + cos^2 (5x) = 0
cos5x * (sin3x + cos5x) = 0
cos5x * (sin3x + sin(pi/2 - 5x)) = 0
cos5x * 2sin(pi/4 - x) * cos(4x - pi/4) = 0
cos5x = 0
5x = pi/2 + pin
x1 = pi/10 + pin/5, n ∈ Z
sin(pi/4 - x) = 0
pi/4 - x = pik
x2 = pi/4 - pik, k ∈ Z
cos(pi/4 + 4x) = 0
4x - pi/4 = pi/2 + pim
4x = 3pi/4 + pim
x3 = 3pi/16 + pim/4, m ∈ Z
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Answers & Comments
Ответ:
Пошаговое объяснение:
sin2x-sin8x = 2*(-sin3x)* cos5x
2*(-sin3x)* cos5x - cos^2 (5x) + sin^2 (5x) - sin^2 (5x) - cos^2 (5x) = 0
2*(-sin3x)* cos5x - 2cos^2 (5x) = 0
sin3x * cos5x + cos^2 (5x) = 0
cos5x * (sin3x + cos5x) = 0
cos5x * (sin3x + sin(pi/2 - 5x)) = 0
cos5x * 2sin(pi/4 - x) * cos(4x - pi/4) = 0
cos5x = 0
5x = pi/2 + pin
x1 = pi/10 + pin/5, n ∈ Z
sin(pi/4 - x) = 0
pi/4 - x = pik
x2 = pi/4 - pik, k ∈ Z
cos(pi/4 + 4x) = 0
4x - pi/4 = pi/2 + pim
4x = 3pi/4 + pim
x3 = 3pi/16 + pim/4, m ∈ Z