sinx=x−x33!+o(x3)
cosx=1−x22!+x44!+o(x4)
tanx=x+x33+o(x3)
arcsinx=x+x33!+o(x3)
arctanx=x−x33+o(x3)
ln(1+x)=x−x22+x33+o(x3)
ex=1+x+x22!+x33!+o(x3)
(1+x)α=1+αx+α(α−1)2!x2+o(x2)