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## Homework Statement

f(x)= x/(1+x)

What is f(f(x)) and what is its domain.

**2. The attempt at a solution**

I found f(f(x))= x/(1+2x)

and the domain: (-∞,-1/2)∪(-1/2,∞) , but it is saying that I have the wrong domain. What mistake have I made?

I found f(f(x))= x/(1+2x)

and the domain: (-∞,-1/2)∪(-1/2,∞) , but it is saying that I have the wrong domain. What mistake have I made?

My process for finding domain:

1. Find the domain of f : x≠-1

2. Use the definition D: {x∈(-∞,-1)∪(-1,∞) | (x/1+x) ≠ -1}

3. Find the ∩ (intersection) for the two domains.