proposition: Lemma tanN x : tan (- x) = - tan x.
proof: Proof. by rewrite /tan sinN cosN mulNr. Qed.
imports: mathcomp(all_ssreflect ssralg ssrint ssrnum matrix) mathcomp(interval rat) mathcomp(mathcomp_extra boolp classical_sets functions) reals ereal nsatz_realtype signed topology normedtype landau sequences derive realfun exp