$\"\"$

The functions are $\"\"$ and $\"\"$ .

The function has a horizontal tangent lines at which the derivative of the function is zero.

Obsrerve the graph:

The parabola curve has zeros at $\"\"$ and $\"\"$ .

The other curve has horizontal tangents at $\"\"$ and $\"\"$ .

Therefore, the parabola curve is derivative function $\"\"$ .

Now label the curves $\"\"$ and $\"\"$ .

Graph the functions $\"\"$ and $\"\"$ and horizontal tangents:

$\"\"$ .

The zeros of $\"\"$ correspond to the points where the graph of $\"\"$ has horizontal tangent line.

$\"\"$

The zeros of $\"\"$ correspond to the points where the graph of $\"\"$ has horizontal tangent line.