[tex]tg(a-b)=\frac{tg a - tg b}{1+tga \cdot tg b} \\
\frac{tg a - tg b}{1+tga \cdot tg b}=\sqrt3 \\
\frac{1 - tg b}{1+tg b}=\sqrt3 \\
\sqrt3 \cdot (1+tgb)=1-tgb \\
\sqrt3+\sqrt3\cdot tgb =1-tgb \\
(\sqrt3-1)tgb=1-\sqrt3 \\
tgb= \frac{1-\sqrt3}{\sqrt3-1}
[/tex]
