Question

tg15градусов+ctg15градусов

Answer 1

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