The graph where the function is decreasing is represented by, the blue line, red line and the green line.
What is decreasing function?
"If the value of the function f(x) is decreasing on increasing the value of x, then the function is called as decreasing function."
For given situation,
we have been given a piecewise function and its graph.
From the graph of a function,
we can observe that the function f(x) is decreasing for x < -3 , -3 ≤ x ≤ 0, and x > 0
This is represented by, the blue line, red line and the green line
Therefore, the correct options are 1, 2, 4.
Learn more about decreasing function here:
https://brainly.com/question/13391696
#SPJ2