Question

Helpful steps please, A vibrating wire has a vertical displacement given by y=8(cos (2 pi x) cos (bt) + sin (2 pi x) sin (bt) ) assume b and t are constant. write y as a cosine function of x

Answer 1

do you want to remove the sine from the function

Answer 2

I believe so

Answer 3

Recall the identity,
\[\cos(x-y)=\cos x\cos y+\sin x\sin y\]

Answer 4

would it then be y=8cos(2 pi x-bt)?

Answer 5

Yep

Answer 6

thanks