Question

вычислите: tg435+tg375

Answer 1

tg435+tg375=(375+475)tg=850tg

Answer 2

$tg435+tg375=\frac{sin(435+375)}{cos435 cos375}=\frac{sin810}{cos435 cos375}=\frac{sin90}{cos75 cos15}$$=\frac{1}{cos75 cos15}=\frac{1}{\frac{cos(75-15) +cos(75+15)}{2}}=\frac{2}{cos60+cos90}=\frac{2}{\frac{1}{2}+0}=4$