10. решите систему уравнений: (3х + зу +1 = х + 4у,7 - 2x + 2y = x — 8y 35 - id140093520200518 от tim27012003 18.05.2020 02:28

Question

Алгебра: 10. решите систему уравнений: (3х + зу +1 = х + 4у,7 - 2x + 2y = x — 8y 35 ​

tim27012003 · Accepted Answer

1) 2Cos(2x-π/6)+√3 = 0
  2Cos(2x-π/6) = -√3
Cos(2x-π/6) = -√3/2
2x-π/6 = +- arcCos(-√3/2) + 2πk , k ∈Z
2x-π/6 = +-5π/6 +2πk , k ∈ Z
2x = +-5π/6 +2πk + π/6 , k ∈ Z
x = +-5π/12 + πk + π/12, k ∈Z
2) Cos(2/3x-1/3) -1=0
Cos(2/3x-1/3) = 1
2/3x-1/3 = 2πk , k ∈ Z
2/3 х = 1/3 + 2πk , k ∈Z
x = 1/2 + 3πk, k ∈Z
3) 3tg(x+5π/36) +√ 3=0
  3tg(x+5π/36) = - √ 3
tg(x+5π/36) = - √ 3/3
х + 5π/36 = -π/6 + πk , k ∈ Z
x =-π/6 + πk - 5π/36  , k ∈ Z
х = -11π/36 + πk , k ∈Z

10. решите систему уравнений: (3х + зу +1 = х + 4у,7 - 2x + 2y = x — 8y 35 ​

MOGZ ответил

10. решите систему уравнений: (3х + зу +1 = х + 4у,7 - 2x + 2y = x — 8y 35