Alongitudinal wave is represented by the equation z(z, t) = -2.0 cm sin(1,200 rad/s t - 20 m -1 z). another longitudinal wave is represented by the equation z(z, t) = +2.0 cm sin(1,200 rad/s t + 20 m -1 z). what is the equation that represents the superposition of the two waves?

z(z, t) = +4.0 cm cos(1,200 rad/s t) cos(20 m-1 z)

z(z, t) = +4.0 cm cos(1,200 rad/s t) sin(20 m-1 z)

z(z, t) = +4.0 cm cos(1,200 rad/s t) cos(20 m-1 z)

z(z, t) = -2.0 cm cos(1,200 rad/s t) sin(20 m-1 z)