High number LIM (x - > 0) TaNx / x ^ 3-x ^ 2-2x why TaNx ~ x ^ 3-x ^ 2-2x ~ (- 2x)

High number LIM (x - > 0) TaNx / x ^ 3-x ^ 2-2x why TaNx ~ x ^ 3-x ^ 2-2x ~ (- 2x)

x-)0;
limsinx/x=1;
So x ~ SiNx;
sinx~tanx(cosx-》0)
So x ~ TaNx;
Because x ~ 0; X & # 179;, X & # 178; are all higher order infinitesimals;
So we can give up;