Question

Write the expression as the sine, cosine, or tangent of an angle.

sin 9x cos x - cos 9x sin x

Answer 1

sin(8x)

Answer 2

Thank you @asaad123

Answer 3

How did you get the answer?

Answer 4

since sin u cos v -cos u sin v =sin (u-v)
sin(9x-x)=sin(8x)