According to the Cauchy's equation,

Question

mu = C + B/((lamda)2)
where C and B are constant and mu and lambda are the wave length and reflective index respectively.

Obtain the suitable least square approximation and �nd the given constant C and B using the following data.

My question is can we use the linear least square approximation since there is one independent variable(lambda) or should we use any other method?

Answer 1

The relation is linear, but in terms of 1/λ ... or is that 1/λ² ?
So I'd use the linear least squares, but label the axes accordingly.