If $f: R \rightarrow R$ is defined by $f(x) = \frac{1}{2 - \cos 3x}$ for each $x \in R$, then the range of $f$ is

If the function $f: R-\{-1, 1\} \rightarrow A$ defined by $f(x) = \frac{x^2}{1-x^2}$ is surjective,then $A$ is equal to

The domain of the function $f(x) = \sqrt{\log_e\left(\frac{1}{x^2-4x+4}\right)} + \sin^{-1}(x^2-2)$ is

The function $f(x) = \operatorname{sech}(x)$ on $R$ has the range

If a real valued function $f:[-1,2] \rightarrow B$ defined by $f(x) = \begin{cases} 1-x, & -1 \leq x \leq 1 \\ x-1, & 1 < x \leq 2 \end{cases}$ is a surjection,then $B=$

The range of the real valued function $f(x) = \frac{x^2 + 2x - 15}{2x^2 + 13x + 15}$ is