Plotting function with multiple limits

I want to plot this function against r and its derivative against r. Can any one help me. Thanks in advance.

[nanren888]

try

help diff

Answer 1

[madhan ravi]

doc diff
doc piecewise

[Muhammadhn Muhammadh Khalid]

Using

piecewise

I couldn't get values for (r/h) with double. how can I solve this?