yintercept: The Start of Your Line
The yintercept of a line is nothing more than an ordered pair. The only special thing about the yint is that the xvalue must be zero.
Examples: 
(0, 5) 
(0, 3) 
(0, 4) 
(0, 18) 
Notice the common trend, the first number (x) is always 0.
Finding the yintercept from an Equation 
To find the yint, plug in x = 0 for your equation, and solve for y.
Example: 

y = 4x + 3 




y = 4(0) + 3 
plug in x = 0 


y = 0 + 3 



y = 3 
solve for y 






(0, 3) 
write the point as (0, y) 

Instead of writing the yint as (0, 3), we can also write it as...
y  intercept = 3, or for short, yint = 3.
The yintercept is also often written as b = 3. We use the letter b to represent the beginning of the line. We use this to help us graph a line in the coordinate plane.
Finding the yintercept from a Table of Values 
A table of values is a list of ordered pairs written as a table...
We want to find the place where x = 0. The matching y value right below there is our yintercept. Take a look...
yint = 2
Sometimes the value where x = 0 will not be shown in the table. In this situation, you will need to continue the pattern until you find x = 0.
x 
2 
4 
6 
8 
10 
y 
5 
8 
11 
14 
17 
Continue the pattern...
I knew that the numbers to the left had to be 0 and 4 because I continued the pattern of adding 2 and adding 3. The yint = 4. 


Finding the yintercept from a Graph 
The yint from a graph is still the y value where x = 0. Luckily, there is a really easy way to find it. Just look for the place where your line crosses the yaxis.
Look for yellow and blue lines to make a green dot...
The yint is the green dot shown above. The xvalue is 0, and the yvalue is 1. That is why the point is (0, 1).
The yintercept is often paired with slope. Learn how to graph using the slope and yintercept or take a look at slope intercept form.
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