MA, Stanford University
Teaching in the San Francisco Bay Area
Alissa is currently a teacher in the San Francisco Bay Area and Brightstorm users love her clear, concise explanations of tough concepts
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MA, Stanford University
Teaching in the San Francisco Bay Area
Alissa is currently a teacher in the San Francisco Bay Area and Brightstorm users love her clear, concise explanations of tough concepts
The x- and y-intercepts of a line, or linear equation intercepts, are often used in problems involving lines and their graphs. Linear equation intercepts are important points to be able to understand and decipher in applications of linear equations problems and can also be used when graphing lines. The y-intercept is used when writing an equation in slope-intercept form.
X and Y intercepts are extremely
important in your study of math.
Before you can get into a good depth of
algebra, you really need to understand
the ideas of X and Y intercepts and
how to find them both from a graph
and from an equation.
So what I have here is just
like a really rough graph.
I just drew a line up there.
There's no numbers or anything.
But what I wanted to show you is that when
you're looking at a graph, you can
find the Y intercept by looking on the
Y axis and seeing where your line
crosses it. That's the Y intercept.
And the X intercept is here. It's where your graph
crosses the X axis.
I'm using int to abbreviate for intercept.
When you think about the coordinates of
this, on your Y intercept, it's going
to be 0 for X, because I'm going 0
side to side and then I'm going up
some number Y. I don't know what
that number is on this particular
graph. But your Y intercept is always when
X is equal to 0. So if all you had
was an equation you would substitute
X equals 0 in order to find your
Y intercept.
Similarly, the value of the coordinates
of the X intercept are going to be some
X value comma 0 for Y. So if I have
an equation and I'm asked to
find the X intercept, I would plug
in Y equals 0.
Before I leave you guys, I want to tell you about one
of the tricks with intercepts is
remembering that to find the X intercept
you'll get Y equals 0. To
find the Y intercept you'll get X
equals 0. It's kind of tricky
but if you can keep it straight in your
head I think you'll do fine on
these problems.
Unit
Linear Equations and Their Graphs