 |
? |
Well, when we
have two variables,
x
and y,
we have a line... and we graph them on a 2-dimensional plane.
So, with three variables,
x,
y
and z,
we'll be in three dimensions... That's 3-D space!
 |
Pretend that the floor of the
room you are in is our old x-y plane... |
 |
The third dimension will be the
vertical line shooting up from the corner of the room. |
This is really
all you need to worry about... unless you're going to take
Calculus 3. (Which is a very cool class, by the way!
Cough - geek!)
So, an equation
like
is a plane that lives in 3-D
space.
With a system of
three equations and three unknowns, we've got three planes in
3-D space. Look in the corner of your room again...
That little corner is THE one point where the two walls and the
floor (or the ceiling -- depending on where you're looking)
intersect.
 |
So, hopefully, we'll get a nice
(x,
y, z)
point like
(1,
-2, 4)
for an answer.
(Check out the "Freaky Things" lesson!) |
This means that
x = 1,
y = -2,
z = 4
will work in ALL three of the original equations you started
with.
