# Math Help - how dy/dx and y2-y1=m(x2-x1) related?

1. ## how dy/dx and y2-y1=m(x2-x1) related?

how dy/dx and y1-y2=m(x2-x1) related?

I mean shouldn't dy/dx = m ?

2. ## Re: how dy/dx and y2-y1=m(x2-x1) related?

The tangent line to a differentiable function at the point $(x_1,y_1)$ is:

$y-y_1=f'(x_1)(x-x_1)$

3. ## Re: how dy/dx and y2-y1=m(x2-x1) related?

Originally Posted by ameerulislam
how dy/dx and y1-y2=m(x2-x1) related?

I mean shouldn't dy/dx = m ?
dy/dx is a FUNCTION which tells you what the gradient of your function y is at any point.

m is the gradient of your tangent line at a SINGLE point.

4. ## Re: how dy/dx and y2-y1=m(x2-x1) related?

Originally Posted by Prove It
dy/dx is a FUNCTION which tells you what the gradient of your function y is at any point.

m is the gradient of your tangent line at a SINGLE point.
If you can please provide an example that would be great! I'm like getting it and not getting it.. tx