Question

Tg(x+y)=5; y Tg(y-z)=4, Calcula ctg(x+z)

Answer 1

Tg(x + y) = 5
Tg(y - z) = 4

Calcular: Ctg(x + z)

Tg(x + y) = 5
Tgx + Tgy = 5
Tgy = 5 - Tgx

Tg(y - z) = 4
Tgy - Tgz = 4
Tgy = 4 + Tgz

5 - Tgx = 4 + Tgz
5 - 4 = Tgx + Tgz
1 = Tg(x + z)

1 = 1/Ctg(x + z)

Ctg(x + z) = 1