Determine every number in the interval $[0,10]$ such that $F(x)=\cot(\pi x)$ is undefined

Determine every number in the interval $[0,10]$ such that $F(x)=\cot(\pi
x)$ is undefined

Determine every number in the interval $[0,10]$ such that $F(x)=\cot(\pi
x)$ is undefined. Justify your reasoning.
Please help this is on my calc homework and I have no idea how to solve this.