Question

tg15градусов+ctg15градусов

Answer 1

$tg 15+ctg 15=\frac{sin 15}{cos 15}+\frac{cos 15}{sin 15}=\frac{sin^2 15+cos^2 15}{sin 15 cos 15}=\frac{1}{sin 15 cos 15}=\frac{2*1}{2sin 15 cos 15}=\frac{2}{sin(2*15)}=\frac{2}{sin(30)}=\frac{2}{0.5}=4$