proposition: Lemma sin_coeff'E x n : sin_coeff' x n = sin_coeff x n.*2.+1.
proof: Proof. by rewrite /sin_coeff' /sin_coeff /= odd_double mul1r -2!mulrA doubleK. 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