Transverse wave and polarization

A taut string was at rest along the X axis, but now a transverse wave of period T, wavelength λ and phase velocity v propagates along it, according to the following equations:
y = Ay cos(k x - ω t)
z = Az cos(k x - ω t + δ)
where k = 2π/λ and ω = 2π/T.