\(f(x)=\frac{2(x +3)}{3}\)
\(\because\) function f(x) is defined for all real values of x.
\(\therefore\) \(- \infty < x< \infty\)
⇒ \(- \infty < x +3 < \infty\)
⇒ \( - \infty <\frac{2(x +3)}{3} < \infty\)
⇒ \(- \infty < f(x) < \infty\)
Range of function f(x) is \(\mathbb {R}\) or \((-\infty, \infty)\).