Answer
$\lambda\times\nu = c$
$\lambda$: wavelength of radiant energy (m)
$\nu$: frequency of radiant energy (1/s)
c: speed of light (m/s)
Work Step by Step
This question asks you to build a relationship between the wavelength ($\lambda$) and frequency ($\nu$) of radiant energy (electromagnetic radiation). Because they are inversely related, and all radiant energy travels at the same speed of light (c), the relationship is written as follows:
$\lambda\times\nu = c$