(tg7п/18 - tg2п/9) / (1+ tg7п/18* tg2п/9)= ?

Question

(tg7п/18 - tg2п/9) / (1+ tg7п/18* tg2п/9)= ?

Answer 1

это формула тангенса разности

(tg7п/18 - tg2п/9) / (1+ tg7п/18* tg2п/9)= tg(7п/18 - 2п/9) = tg(П/6) = 1/корень из 3