Ответ :

Ответ:

nє(-∞;1/3]U[3;+∞)

Объяснение:

  • 2sin(x)=(n+1)/(n-1)
  • sin(x)=(n+1)/2(n-1)
  • sin(x)=(n+1)/(2n-2)
  • -1≤sin(x)≤1
  • -1≤(n+1)/(2n-2)≤1

  • 1)-1≤(n+1)/(2n-2)

(n+1)/(2n-2)≥-1

(n+1)/(2n-2) + 1≥0

(n+1)/(2n-2) + (2n-2)/(2n-2) ≥0

(n+1+2n-2)/(2n-2)≥0

(3n-1)/(2n-2)≥0

ОДЗ: 2n-2≠0

(2n≠2,n≠1)

(3n-1)*(2n-2)≥0 (n≠1)

(n-1/3)*(n-1)≥0 (n≠1)

+. —. +.

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1/3. 1. n

nє(-∞;1/3]U(1;+∞)

  • 2)(n+1)/(2n-2)≤1

(n+1)/(2n-2)-1≤0

(n+1)/(2n-2)-(2n-2)/(2n-2)≤0

(n+1-2n+2)/(2n-2)≤0

(-n+3)/(2n-2)≤0

(n-3)/(2n-2)≥0

ОДЗ:2n-2≠0

2n≠2, n≠1

(n-3)*(2n-2)≥0 (n≠1)

(n-3)*(n-1)≥0. (n≠1)

+. —. +.

--------o-----------•-----------›

1. 3. n

nє(-∞;1)U[3;+∞)

  • объединяем:

nє(-∞;1/3]U(1;+∞) и nє(-∞;1)U[3;+∞)

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------------•----------о-------------•----------------›

////////////////////////. ////////////////// n

значит nє(-∞;1/3]U[3;+∞)

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