Answer :

[tex]csc60^o=\frac{1}{sin60^o}=\frac{1}{\frac{\sqrt3}{2}}=\frac{2}{\sqrt3}=\frac{2}{\sqrt3}\cdot\frac{\sqrt3}{\sqrt3}=\frac{2\sqrt3}{3}[/tex]
1/sin60
= 2/√3
= 2√3/3