Question

What is the equation of the line normal to `f(x)=xln(x^3-x)` at `x=1`?

Answer 1

I am not sure you can have it. The function is not defined at `x=1`!

Explanation:

At `x=1` you have `ln0`...!

Graphically:
graph{xln(x^3-x) [-18.02, 18.03, -9.01, 9.01]}