**Guide :High School **

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

Write the expression as the sine, cosine, or tangent of an angle. sin 9x cos x - cos 9x sin x**If we know thatSin( x + y) = Sin(x) Cos(y) - Cos(x)Sin(y)then sin 9x cos x - cos 9x sin x -> Sin(9x+X) = Sin(10X)**...