Which one of the following graph represents the function $$f(x) = {x \over x},x \ne 0$$ ?

Let $$f(n) = \left[ {{1 \over 4} + {n \over {1000}}} \right]$$, where [x] denote the integral part of x. Then the value of $$\sum\limits_{n = 1}^{1000} {f(n)} $$ is

If $$f(x) = {{4x + {x^4}} \over {1 + 4{x^3}}}$$ and $$g(x) = \ln \left( {{{1 + x} \over {1 - x}}} \right)$$, then what is the value of $$(fog)\left( {{{e - 1} \over {e + 1}}} \right)$$ equal to ?

If $$f(x) = {x \over {x - 1}}$$, then what is $${{f(a)} \over {f(a + 1)}}$$ equal to ?