Answer :

fierrojose8
Wavelength (L) is equal to the Speed of Light (c) divided by the Frequency (f) ; L = c / f

L = (299,792,458 m/s) / (750E12 Hz) = 3.9972E-7 = 399.72E-9
or roughly 400 nanometers
AL2006
Wavelength of any wave = (speed) / (frequency)

Speed of light = 300,000,000 m/sec

Wavelength = 3 x 10 to the 8 / 750 x 10 to the 12 = 4 x 10 to the -7 or 400 nanometers.