The interval, used on the graph plot, to produce the graph is
π/2 ≤ θ ≤ π
How to find the interval
The interval is solved by checking the quadrant the entire graph is located.
From the graph, we can see that the graph is located on the second quadrant. In this quadrant, the angel covered here in degrees is 90 to 180 degrees. This is written in radians as π/2 ≤ θ ≤ π
Since π/2 is 90 degrees and π is 180 degrees.
Therefore, we can say that the interval that produce the graph is
π/2 ≤ θ ≤ π