Задание 15.6

15.6. Решите уравнение: 1) cos (π 9 4x) = 1; 2) 2cos (x 2 + 3) + 1 = 0

Answers

1.
cos (π 9 4x) = 1 π 9 4x = ±arccos 1 + 2πn 4x = π 9 ± arccos 1 + 2πn 4x = π 9 + 2πn x = π 36 + 1 2πn,n


2.
2cos (x 2 + 3) + 1 = 0 cos (x 2 + 3) = 1 2 x 2 + 3 = ±arccos ( 1 2 ) + 2πn x 2 + 3 = ±3π 4 + 2πn x 2 = ±3π 4 3 + 2πn x = ±3π 2 6 + 4πn,n

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2021-11-23 13:55
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