Dear all, 
I'm a Mathematica beginner and I'm struggling with plotting a nested function. 
I have a function f[x,p] - and the variable p is also a function of x. So I basically want to plot a function f[x,f[x]]. So far, I have tried the following things: 
a) First, I defined the variable p=... such that if I enter p, I get the right expression with the unknown parameter x. Second, I entered the function f[x,p] - but I do not get any output for that. 
b) I defined a function h[x] instead of the variable p and substituted all p in f[x,p] by h[x], such that f[x,h[x]]=... is a function of x and h[x] which leads to the error "pattern x appears on the right hand side.
c) Finally, I plugged the expression of h[x] in f[x,h[x]] such that I only have f[x]. But in this case I get "construct pure function". 
I am happy for any hint!
Thank you in advance
Patrick