The inequality is
.
Consider
.
Now, there are two ways this product could be less than zero.One factor must be negative or equals to zero and one must be positive or equals to zero.
\Case 1 :
\
and 
and 
There are NO values for which this notation is true.
\Case 2 :
\
and 
and
.
Solution set is
.
The solution in interval notation
.
The solution in interval notation
.