Who gave the speed of light, wavelength and frequency relationship ?

Question

c = f * lambda - this equation was given by whom????

which equation tells us about the particle nature of the body ?????

Answer 1

iam guessing it

       is it a de-broglie's equation?

if iam wrong then let me know

thanks

Answer 2

The relationship between the speed of a wave, the frequency and the wavelength goes back to antiquity.  

v = f x lambda is true for either mechanical waves or light waves.

The debate of the wave vs particle nature of light goes back to Newton and Huygens in the 1600's.

Huygens said that light was a wave and Newton maintained that light was a stream of particles.  Neither was exactly right since light can have properties of both.

A more modern connection of waves and particles deals with the wave nature of electrons (and particles in general) as proposed by de Broglie (pronounced de Broy) in the early 1900's.

wavelength = Planck's constant / momemtum

lambda = h / mv