# Question #914c6

##### 1 Answer

- the number of wavelengths per unit distance,
#1/lambda = f/c# - the number of radians per unit distance.

#### Explanation:

- I think you need the following :

#1/lambda = f/c#

Where#1/λ # is equal to the wave number,

#f# and#c# are frequency and wave speed respectively.

It is denoted as

This definition is normally used in spectroscopy.

2. In wave equations where frequency, wavelength and wave-number are constants, it is defined as angular wave-number or simply called wave-number, represented by