Respuesta :

Just need to put zero instead of y and solve the equation for find the value of x :

0 = 2 Cot ( x/4 )

Cot ( x/4 ) = 0

Cot ( x/4 ) = Cot ( π / 2 )

x / 4 = π / 2

x = 4 × π / 2

x = 2π

Thus the correct option is C .