Initial value of Newton Raphson Method I am currently studying Newton-Raphson Method. I feel that I understand the concept of it.
Somehow, I am facing some question in my head about how to actually apply it.
The questions that I have are below
- How should I decide the first initial value?
- How should I find all the roots on x-axis?, how should I set the ranges to find them separately?
Please, let me here your expertise. I am sorry if I have tagged my question in the wrong places.
Thank you. 

Actually guessing proper initial value is helpful to find the root in less iteration. Improper guess of initial value can increase the number of iteration but surely generate the root(if the root can be found by Newton Raphson Method) after some more iteration.
I found an easy way to guess comparatively more suitable initial value: Draw the graph of the function and consider a point close to the zero crossing point of the function in X axis. 
