Question

when we take cos function in equation of wave instead of sin function?​

Answer 1

When in the question, at time t = 0 and x = 0
The source is at the y - axial amplitude position, then because the wave is already π/2 ahead in phase than a normal wave, we use sin (wt+π/2) = cos wt
hope this helps you !

Answer 2

Actually, in the mathematics sine and cosine functions are defined based on right angled triangles. But how will the representation of a wave or signal say based on these trigonometric functions (we can't draw any right angled triangles in the media, i.e., the air) then how can we say that?

Hope it helps u mark as brainliest please