Question

i dont understand what the graph and equation is the same

Answer 1

From the graph we can conclude:

For;

$x<2$

The function is a parabola centered at the origin and shifted 4 units up, therefore:

$y=x^2+4$

And for:

$x\ge2$

The function is a line which slope is -1 and its y-intercept is 4, so:

$y=-x+4$

Answer:

$y=\begin{cases}x^2+4,_{\text{ }}x<2 \\ -x+4,_{\text{ }}x\ge2\end{cases}$