A book with many printing errors contains four different formulas for the displacement y of a particle undergoing a certain periodic motion :
(a) y=asin 2πᵗ/ᵀ
(b) y = a sin vt
(c) y = (a/T) sin t/a
(d) y = (a/√2) (sin 2π / T + cos 2π / T)
(a = maximum displacement of the particle, v = speed of the particle. T = time-period of motion). Rule out the wrong formulas on dimensional grounds.