4sinx-2>0

2tg 2x+8>0

5cos 2 x+2<7

есть ли решение у этих уравнений

1) 4sinx > 2

sinx > 1/2

arcsin (1/2) + 2πn < x < π - arcsin (1/2) + 2πn, n∈Z

π/6 + 2πn < x < π - π/6 + 2πn, n∈Z

π/6 + 2πn < x < 5π/6 + 2πn, n∈Z

2) 2tg 2x + 8> 0

tg2x > - 4

- arctg4 + πk < 2x < π/2 + πk, k∈Z

- (1/2) * arctg4 + (πk) / 2 < x < π/4 + (πk) / 2, k∈Z,

3) 5cos 2 x+2<7

5 cos2x < 5

cosx < 1

arccos (1) + 2πm < 2x < 2π - arccos (1) + 2πm, m∈Z

0 + 2πm < 2x < 2π - 0 + 2πm, m∈Z

2πm < 2x < 2π + 2πm, m∈Z

πm < x <π + πm, m∈Z