toiyeutoanhoc12345

Với mỗi ánh xạ $f$ cho dưới đây, hãy tìm $f\left ( 1 \right ), f^{-1}\left ( 1 \right ), f\left ( \left ( 0, 1 \right ) \right ), f^{-1}\left ( \left ( 0, 1 \right ) \right ),$ và $\operatorname{Im}f$

$\begin{array}{cl} {\rm a}. f: & \mathbb{R}\rightarrow\mathbb{R}\\ \, & x\rightarrow f\left ( x \right )= x^{2}+ 4x- 5 \end{array}$

$\begin{array}{cl} {\rm b}. f: & \mathbb{R}\setminus\left \{ 0 \right \}\rightarrow\mathbb{R}\\ \, & x\rightarrow f\left ( x \right )= x^{3}+ x^{-3}+ x+ x^{-1} \end{array}$