Bfui gnoc so Sdjflk JsdkfK J Jlk JjLkj Kjlk Jl JklJkl Jlk Jlk JklJl Jkl Jl JlKjk Lj Lj LkjLk Jkl Jl KjLkj Lj lk(x+a)n=∑k=0n(nk)xkd an−k(1+ x ê)n=1+nx1!+n(n đ −1)d x22 ! đ+…sin α ± sin β=2 sin12(α ± β)cos12(α∓ β)