Respuesta :

1 + tan^2(11pi/6)
1 + tan^2(2pi - pi/6)
1 + tan(2pi - pi/6)*tan(2pi - pi/6)

tan(2pi) = 0
tan(pi/6) = 1/sqrt(3)

Compund angle rule:

1 + sqrt(3)/3 * sqrt(3)/3
1 + 1/3
4/3