1+sin a +cos a +tg a = (1+cos a) (1+tg a) доведіть тотожність
1+sin a +cos a +tg a = (1+cos a) (1+tg a) tg a = sin a / cos a 1+sin a +cos a +sin a / cos a=(1+cos a) (1+sin a / cos a) 1+sin a +cos a +sin a / cos a=1+sin a +cos a +sin a / cos a