How do you use and find the y-intercept?
The y-intercept of a graph is the y-coordinate of the point where the graph crosses the y-axis.
In the diagram the point where the graph crosses the y-axis is P. Since P is on the y-axis its coordinates are (0,b) for some number b. b is the y-intercept.
To find the y-intercept substitute x = 0 in the equation and solve for y. For example if you have the graph of