By definition, the slope or gradient of a line describes its steepness, incline, or grade.
Where
m — slope
θ — angle of inclineSlope (m) =-0.1
θ =354.2894068625°
distance (d) =10.049875621121
ΔX =10
ΔY =-1
And no its not undefined, if it was, the X's would be the same number