Locating y-intercepts from graphs | Grade 8 (TX) | Khan Academy

All right, let's get some practice identifying Y intercepts. Just as a hint, the Y intercept is where a line intersects the Y axis. So pause this video and think about what is the Y intercept of this blue line.

All right, so where is this line intersecting the Y axis? It's doing it right over there. Now, there are two ways that you can say what the Y intercept is. Some people will just give you the Y value; they'll just say the Y intercept is equal to, in this case, six, because that is the Y value.

Or they'll just give you the coordinates. They could also say the Y intercept is the point (0,6), but either way, that point right over there (0,6) or when Y equals 6, that's the Y intercept.

Let's do another example here. What is the Y intercept here? Pause the video, try to figure it out. Well, this line intersects the Y axis right over here. That looks like it is the point (0,3).

And actually, if we're talking about a Y intercept, X is always going to be equal to zero because that's when we are on the Y axis. The Y value here is, we can notice, it's halfway between 2 and 4. It is right there at 3, so we could say the Y intercept is (0,3), or some people would say that the Y intercept, maybe Y, in for short, is equal to 3. Once again, two ways to communicate that.

Let's do one more example. I don't know where this little red splot came from, but let's ignore it. What is the Y intercept for this line? Well, we're intersecting the Y axis right over there. That is the point (0,-3.5) because X is going to be equal to zero since we are on the Y axis, and Y looks like it is halfway between -3 and -4, so it's -3.5 or some people would say that the Y intercept is -3.5.