The number of functions $f: \{1, 2, 3, 4\} \to \{a, b, c\}$, which are not onto, is:

The functions which map $[-1, 1]$ to $[0, 2]$ are

If $A = \{x \mid x \in N, x \leq 5\}$ and $B = \{x \mid x \in Z, x^{2} - 5x + 6 = 0\}$,then the number of onto functions from $A$ to $B$ is:

If $f(x) = \begin{cases} x, & \text{when } x \text{ is rational} \\ 0, & \text{when } x \text{ is irrational} \end{cases}$ and $g(x) = \begin{cases} 0, & \text{when } x \text{ is rational} \\ x, & \text{when } x \text{ is irrational} \end{cases}$,then $(f - g)$ is:

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

Prove that the function $f: R \rightarrow R$,defined by $f(x)=2x$,is one-one and onto.