Let $[ x ]$ be the greatest integer $\leq x$. Then the number of points in the interval $( - 2,1 )$ where the function $f ( x ) = | [ x ] | + \sqrt { x - [ x ] }$ is discontinuous, is $\_\_\_\_$ .
Let $[ x ]$ be the greatest integer $\leq x$. Then the number of points in the interval $( - 2,1 )$ where the function $f ( x ) = | [ x ] | + \sqrt { x - [ x ] }$ is discontinuous, is $\_\_\_\_$ .