You haven't provided a graph or equation so I will tell the simplified meaning of amplitude instead.
Amplitude, is basically a distance from midline/baseline to the maximum or minimum point.
For sine function, can be written as:
[tex] \displaystyle \large{ y = A \sin(bx - c) + d}[/tex]
I am not able to provide an attachment for an easy view but I will try my best!
We know that amplitude or A is a distance from baseline/midline to the max-min point.
Let's see the example of equation:
[tex] \displaystyle \large{y = 2 \sin x}[/tex]
Refer to the equation above:
Thus, the baseline or midline is y = 0 or x-axis.
You can also plot the graph on desmos, y = 2sinx and you will see that the sine graph has max points at 2 and min points at = -2. They are amplitude.
So to conclude or say this:
If Amplitude = A from y = Asin(x), then the range of function will always be -A ≤ y ≤ A and have max points at A; min points at -A.