Question

does any one know what the formula for slope is?

Answer 1

slope of any thing is the slope of tangent at that point on the curve.
of-course if here you are referring for a st line, the tangent is the st line itself!!

for its slope, we re-write the equation in the form of y = mx +c, then here, 'm' is the slope value. if you want an example, do tell.

Answer 2

Watch this if you need more info
http://www.khanacademy.org/math/algebra/linear-equations-and-inequalitie/v/slope-of-a-line