From the theory we know that:
c = λ / T
f = 1 / T
Where:
c = 3.[tex]10^{8}[/tex] / m (the speed of light)
λ is the wavelengh (in meters)
T is the period (in seconds)
f is the frequency (in Hz)
We were told that:
f = 7.30 . [tex]10^{14}[/tex]
And we want to find out the value of λ.
c = λ / T
c = λ . 1/T
Swaping 1/T = f
c = λ . f
λ = c / f
λ = 3 . [tex]10^{8}[/tex] / 7.30 . [tex]10^{14}[/tex]
λ = 4.12 [tex]10^{-7}[/tex] m
Response: 4.12 [tex]10^{-7}[/tex] m = 412 nm
:-)