Question

упростите выражение: cosa+ctga/1+sina

Answer 1

$frac{Cosalpha+Ctgalpha}{1+Sinalpha}=frac{Cosalpha+frac{Cosalpha}{Sinalpha}}{1+Sinalpha }=frac{frac{Sinalpha Cosalpha+Cosalpha}{Sinalpha}}{1+Sinalpha}= frac{Cosalpha(Sinalpha+1)}{Sinalpha(1+Sinalpha)}=frac{Cosalpha }{Sinalpha }=Ctgalpha$