1) Вычислить
sin110°*cos220°
/ ctq330° =sin(90°+20°)*cos(180° + 40°)
/ ctq (360° -30°)=
cos20°*(- cos40°)
/ ( -ctq30°) =(
cos20°* cos40°)
/√ 3 =(cos20°+ cos60°)
/2√
3 =(cos20°+ 1/2)
/ 2√ 3 = (2cos20°+ 1)
/ 4√ 3 = (2cos20°+ 1)√
3 / 12....................
ой поле кончилось
другое дело
cos20°cos40°cos80° = sin20°cos20°cos40°cos80°
/ sin20° =
sin40°cos40°cos80°
/ 2sin20° = sin80°cos80°
/ 4sin20° = sin160°
/ 8sin20° =sin(180° -20°)
/ 8sin20° =sin20° / 8sin20°
= 1/8 .
2) см приложение
Удачи !
