The sign between two terms in argument of sine will define its direction.

Writing the given wave equation

y = 0.25 sin (10 π π x – 2 π π t) ....(i)

The minus (–) between (10 π π x) and (2 π π t) implies that the wave is travelling along positive x direction.

Now comparing Eq. (i) with standard wave equation

y = a sin (kx – t) ...(ii)

We have

a = 0.25 m, ꞷ = 2 π π , k = 10 π π m

∴ = 2 π π

⇒ ƒ = 1 Hz

Also, λ λ = = 0.2 m

Therefore, the wave is travelling along +ve x direction with frequency 1 Hz and wavelength 0.2 m.