I have the relation λ=c/f, respectively f=c/λ and a simple function n[λ_]:=λ²+1. I'd like to differentiate the function with respect to f, then plot it as a function of λ again. For this, I can define the function n[λ_]:=λ²+1 I can now compute D[n[c/f], f] To get that as a function of λ, I tried nplot[f_]:=D[n[c/f], f] (which does not work) and then Plot[nplot[c/f],{f,a,b}] Is there no elegant way to switch between λ and f in plotting and computing - such, that I could just say derivative[f]=D[n[f],f] Plot[derivative[λ],{λ,0,10}] …? Login To add answer/comment