Question

If $x\ne 1$ and $f(x)=\frac{x+1}{x-1}$ is a real function, then $fff(2)$ is:

• A. 1
• B. 2
• C. 3
• D. 4
• E. none of these

Answer 1

Answer: (C)

$\because$ $f(x)=\frac{x+1}{x-1}$ $\therefore$ $f(2)=\frac{2+1}{2-1}=3$ $f\{f(2)\}=f(3)=\frac{3+1}{3-1}=\frac{4}{2}=2$ and $f[f\{f(2)\}]=f(2)=\frac{2+1}{2-1}=3$