Преобразовать в произведение 1-tg(a)-sec(a)

1 - tg(a) - sec(a) = cos(a)/cos(a) - sin(a)/cos(a) - 1/cos(a) = (cos(a) - sin(a) - 1)/cos(a)

1-tg-sin=1-sin/cos- sin=cos-sin/cos - sin= cos-sin-sin/cos= cos-2sin/cos=cos/cos-2sin=1-2sin