[tex]\begin{gathered} c=f\wedge \\ \text{where} \\ \wedge=wavelength \\ f=\text{frequency} \\ c=propagation\text{ sp}eed\text{ of the wave} \end{gathered}[/tex][tex]\begin{gathered} c=3\times10^8 \\ f\text{ =?} \\ \wedge=1\times10^{-12} \end{gathered}[/tex]
Therefore,
[tex]\begin{gathered} f=\frac{c}{\wedge} \\ f=\frac{3\times10^8}{1\times10^{-12}} \\ f=3\times10^{8-(-12)} \\ f=3\times10^{20}s^{-1} \end{gathered}[/tex]
