First of all, you can graph any equation into Desmos. Just type in an equation and it will graph it correctly.
To find the interval (how much the graph covers), graph the equation then look at what x-values the function covers.
As you can see the function covers everything from -8 to 2 on the x-axis.
Therefore, the interval is [-8,2]
The interval is in brackets because it includes both -8 and 2 in the function.
If it did not include -8 or 2 but everything in between the interval would be (-8,2)
