Answer: On interval f(x) is increasing =  [tex]( -\infty, -2)[/tex] 
On interval f(x) is decreasing = [tex]( -\infty, -2)[/tex] 
Step-by-step explanation:
The given function: [tex]f(x)=-(x+2)^2+4[/tex]
The graph of the function is attached below 
In graph , function is increasing till point (-2,4) or x=-2 and then it is decreasing.
So f(x) is increasing in [tex]( -\infty, -2)[/tex] and decreasing in [tex](-2, \infty)[/tex]
So, On interval f(x) is increasing =  [tex]( -\infty, -2)[/tex] 
On interval f(x) is decreasing = [tex]( -\infty, -2)[/tex]