Question

Can you get an extremely high gradient of a straight line for instance:

m = 14375

I used the formula (y2-y1)/(x2-x1)

or have I miscalculated?

Answer 1

yes, of course. What you are ignoring is what units is the gradient.

For instance 12375 nanometers/mile is a pretty level road. However, 12375meters/mile is a rather steep road.