It is said that Indicator Function can't be differentiated. I could not get the logic behind it. Even if we define $0<x<\theta$ such function can't be differentiated.
Well the question is A random sample of size n is taken from distribution with pdf f ( x ) = 2 x / θ^2 ;0 < x < θ = 0 otherwise
Now professor is saying that the equation is not differentiable. So can somebody help here with logic that why it is not differentiable.