Equation of a stationary and travelling waves are as follows y1 = asinkxcosωt, and y2 = asin(ωt - kx). The phase difference between two points x1 = π/3k and x2 = 3π/2k is ϕ1 in the standing wave (y1) and is ϕ2 in travelling wave (y2) then ratio ϕ1/ϕ2 is
(a) 6/7
(b) 1
(c) 5/6
(d) none
