If f(x) is continuous and f$\left(\frac{9}{2}\right)$=$\frac{2}{9}$ , then $\underset{x\to 0}{\lim }f\left(\frac{1-\cos 3x}{x^2}\right)$ is equal to

$$\begin{gathered} \mathrm{f}\left(\mathrm{x}\right) \mathrm{is} \mathrm{continuous}, \mathrm{f}(9/2)=\frac{2}{9}. \\ \mathrm{then} \underset{\mathrm{x}\to 0}{\lim }\mathrm{f}\left(\frac{1-\cos 3\mathrm{x}}{{\mathrm{x}}^2}\right)=\mathrm{f}\left(\underset{\mathrm{x}\to 0}{\lim }\frac{1-\cos 3\mathrm{x}}{{\mathrm{x}}^2}\right) \\ =\mathrm{f}\left(\underset{\mathrm{x}\to 0}{\lim }\frac{3 \sin 3\mathrm{x}}{2\mathrm{x}}\right)=\mathrm{f}\left(3\times \frac{3}{2}\right) \\ =\mathrm{f}\left(\frac{9}{2}\right)=\frac{2}{9} \end{gathered}$$