Limit calculation of advanced mathematics lim tanx-sinx / x^3 x→0

Limit calculation of advanced mathematics lim tanx-sinx / x^3 x→0

Equivalent infinitesimal
= sinx(1-cosx)/(x^3 cosx)
= x*x^2/2 /(x^3 cosx)
=1/2
The middle limit sign is omitted