# Math Help - decimal expansion

1. ## decimal expansion

Suppose that a element J has decimal expansion 17:3491400238:::, so that f(a) = 4.
Can you name  delta > 0 such that /f(x)f(a)/ < 1 for all x element J such that /x-a/ < delta ? the answer for delta is 1/10^8 but dont know how to prove it?

2. ## Re: decimal expansion

Originally Posted by sbacon1991
Suppose that a element J has decimal expansion 17:3491400238:::, so that f(a) = 4.
Can you name delta > 0 such that /f(x)f(a)/ < 1 for all x element J such that /x-a/ < delta ? the answer for delta is 1/10^8 but dont know how to prove it?
Is that the complete question as worded in the book/sheet? Some context might also help.

CB