If the domain and range of $f(x){ = ^{9 – x}}{C_{x – 1}}$ contains $m$ and $n$ elements respectively, then 

If $f\left( x \right) = {\left( {\frac{3}{5}} \right)^x} + {\left( {\frac{4}{5}} \right)^x} – 1$ , $x \in R$ , then the equation $f(x) = 0$ has

A real valued function $f(x)$ satisfies the function equation $f(x – y) = f(x)f(y) – f(a – x)f(a + y)$ where a is a given constant and $f(0) = 1$, $f(2a – x)$ is equal to

If $f( x + y )=f( x ) f( y )$ and $\sum \limits_{ x =1}^{\infty} f( x )=2, x , y \in N$ where $N$ is the set of all natural numbers, then the value of $\frac{f(4)}{f(2)}$ is

Function $f(x)={\left( {1 + \frac{1}{x}} \right)^x}$ then Range of the function f (x) is