Here we need to learn how to read a graph.
In a normal graph we have the inputs (the values of x) in the horizontal axis and the outputs in the vertical axis.
Here we want to see what is the value of y for the blue graph when x = 2.5
We will find y = -1.5
(the blue graph is the one that corresponds to: y = x^2 - 2x - 3)
To find this:
The first thing we need to do is find x = 2.5 in the horizontal axis.
Now that we found it, we need to draw a vertical line, and see at which point of the blue graph this vertical line intersects the curve. At that point we draw an horizontal line that intercepts the vertical axis.
At that point we have the y-value
You can see an example of this, a good estimation by only looking at the graph is y = -1.5
For the other point, the value of x when y = 1.
We do exactly the same thing but in the inverse order, we first find y = 1
Then we draw an horizontal line that intercepts the graph
Then we draw a vertical line that intercepts the x-axis and we find the value.
We can see that for y = 1 we have x = 3.2 aprox.
If you want to learn more you can read:
https://brainly.com/question/16781210
