tg(x/2) = -1
tg(x/2) = -1
x/2 = -π/4 + kπ
x = -π/2 + 2kπ

2sin(x/3) = 1
sin(x/3) = 1/2
x/3 = π/6 + 2kπ or x/3 = π - π/6 + 2kπ
x = π/2 + 6kπ or x = 5π/2 + 6kπ

cos(5x) + 1 = 0
cos(5x) = -1
5x = π + 2kπ or 5x = 3π + 2kπ
x = π/5 + 2kπ or x = 3π/5 + 2kπ

3tg(xπ/4) = √3
tg(xπ/4) = √3/3
xπ/4 = π/6 + kπ or xπ/4 = 5π/6 + kπ
x = 4π/6 + 4kπ or x = 20π/6 + 4kπ

ctg(2x/3) = 0
1/tg(2x/3) = 0
tg(2x/3) = ∞
2x/3 = π/2 + kπ
x = 3π/4 + 3kπ

1 - sin(x/3) = 0
sin(x/3) = 1
x/3 = π/2 + 2kπ
x = 3π/2 + 6kπ