You say "where x is a number" but then you talk about the standard deviation of x - which implies x is either a random variable or a vector of results. Can you reword what you're trying to say?
this is true, x is a vector with a standard deviation. It is infact a 2D coordinate position.
So, I have :
x = [ 20 ; 34555] +/- 255
where 255 is the standard deviation.
Now,I know that my vector x tends to infinity and I am getting a rather large standard deviation for it, which I think means that there is high uncertainty associated with 'x' (or at least this is what I assume ,not 100% sure on that).
Can I make the assumption that if x tends to infinity , then its standard deviation(i.e.precision) will tend to zero?
Without knowing more or making additional assumptions I don't see how you could assume that.
Also note that precision is 1/standarddeviation which might be what's causing part of my confusion with your problem. You keep saying that the standard deviation grows as x gets large and then you say that you want to make the claim that the standard deviation goes to 0 as x gets large - which contradicts what you previously said...