Sin 8x-Sin 6x+Cos 7x

Sin 8x-Sin 6x+Cos 7x=(128 cos^7 x-224cos^5 x+112cos^3 x-14cosx)*sinx+64cos^7 x-112cos^5 x+56cos^3 x-7cosx=(-((-128)*cos^7 x+224cos^5x+(-112)*cos^3x+14cosx))*sinx+64cos^7x+(-112)*cos^5x+56cos^3x-7cosx=sin(8x)+cos(7x)-sin(6x)