1) ctg 2,5x = -1/√3
2,5x = arcctg(-1/√3) + πn, n∈Z
2,5x = 2π/3 + πn, n∈Z
x = 4π/15 + 2πn/5, n∈Z
2) sin x = -0,6
x = (-1)(n +1)*arcsin(0,6) + 2πk, k∈Z
3) tg (-x+π/3) = √3
- tg(x - π/3) = √3
tg(x - π/3) = - √3
x - π/3 = arctg((- √3) + πm, m∈Z
x - π/3 = - π/3 + πm, m∈Z
x = - π/3 + π/3 + πm, m∈Z
x = πm, m∈Z