Newton Rhapson - this one

I decided to repost this as the previous one went crazy.......

I'm trying to construct an iterative procedure NR1(f,x0,N) where f is a function, x0 is an initial estimate (which can be complex) and N the number of iterates.

Given:  x_k+1=x_k - f(x_k)/f'(x_k), k=0,1,2....,

Now for example by defining f:= x-> x^2-2 and inputting x₀=1 and N=10 i should be able to check that my procedure calculates sqrt(2) correctly.

This is what i've got so far.....

NR1:= proc(f,x0,N)
> local x,k,f:
> x := x0:
> for k to N do:
>   x := x-f/D(f)
> end do:
>  evalf(x):
> end proc:f:= x-> x^2-2:
> NR1(f,1,10);
 

Could someone point out where i'm going wrong?

Thanks.