como hago esta identidad y es igual a =tangt
$${\mathtt{sent}}{\mathtt{\,-\,}}{\frac{\left({\mathtt{2}}{\mathtt{\,\times\,}}{{\mathtt{sen}}}^{{\mathtt{3}}}{\mathtt{\,\times\,}}{\mathtt{t}}\right)}{\left({\mathtt{2}}{\mathtt{\,\times\,}}{{cos}\left(}^{{\mathtt{3}}}{\mathtt{\,\times\,}}{\mathtt{t}}\right)}}{\mathtt{\,-\,}}{\mathtt{cost}}$$
