[Becky]

I am a Mathly chalanged 17 year old who should never have past first grade math (homeschooled ).

I need help!

Enyone able to explain how to get the equation of a line?
Slope/intercept formula?

[Jay Tea]

How to get the equation of a line depends on what information you start with...what do you have?

[nate95366]

Slope-Intercept Form

y=m(x) + b

Follow along with this on a 2-dimensional graph (x-y coordinate graph):

y is called the "dependent" variable because the y coordinate is dependent on what the x value is that you're putting into the equation.

x is called the "independent" variable

m is the slope. Slope is thought of on a line as: "How far does the line go up or down each time we move one x-unit left or right?" If you draw a line through the coordinates (0,0), (1,1), (2,2).... you see that you go up or down 1 for every unit that you move left or right... A slope is "positive" if it's "pointing up and right" and "negative" if it's "pointing up and left." You'll notice that the patterns on most men's neckties are negative-sloped...

b is the y-intercept, the point at which the graph of the line crosses the y-axis.

So....... if I have this equation: y=3x + 5

I know two things for sure:
1) The slope of the line will be 3, and it's positive (since 3 is a positive number)
2) The graph will cross the y axis at (0,5)

And if I have this equation: y=-2x - 3

I know that:
1) The slope of the line is -2
2) The graph will cross the y axis at (0,-3)


Does any of that help???


Nate

[froggee501]

listen to Nate, he said everything I would have said, except in more detail, and probably better.

[Becky]

I get it!!! I actualy understand!!! Its a mirical!!!

Now all I need is to learn every other point in math

Thanks!

[nate95366]

Victory!!!!! (at least in battle, it appears the war has yet to be won...???)

:kgrin: :kgrin: :kgrin: :kgrin: :kgrin: