what does this equation do?

Question

y1 - y2 / x1 - x2

Or is it

x1 - x2 / y1 - y2?

Answer 1

rise over run! it's the slope of a line!

Answer 2

I think the equation you actually mean is:
(y1-y2)/(x1-x2)

i.e.

y1-y2
--------
x1-x2

This is the method of calculating the slope of a line when you know two points (x1,y1) and (x2,y2)

The formula in question is used in the equation of a basic line:
y=mx+b

where:
m is the slope of the line and;
b is the y-intercept (where the line intercepts the y-axis (i.e. what the value of y is when x=0))

Answer 3

It is the slope of a line, but more generally:

When X1->X2, meaning when X1 is very close to X2, X1-X2 = dX, and subsequently: Y1-Y2 = dY, if Y2 = f(X2) and Y1=f(X1), where f(X)=Y is any given, continuous function.

Therefore: (Y1-Y2)/(X1-X2) = dY/dX = df(X=X0)/dX if X2---> X1. df(X=X0)/dX is the slope of the tangent to f(X) at X=X0. When f(X) is a line y=mx+h, then df(X=X0)/dx is the slope of the line itself, since the tangent to f(X) and f(X) are one and the same!

Answer 4

y2-y1/x2-x1 measures the slope of a line if thats what you mean?

Answer 5

Point -Slope form of the equation of a line

m = y₂- y₁/ x₂- x₁

Answer 6

That is the slope formula. You will find this equation in Algebra.

Answer 7

slope of a line

Answer 8

mystifies me