Compton scattering fractional wavelength change with blue light and X-rays

[ehrenfest]

1. Homework Statement [/b
Robinett question
One of my homework questions in the Compton scattering section asks:

"Evaluate the fractional change in wavelength delta lambda/lamdba, for incident blue light and X-rays? It also gives the wavelength of blue light and X-rays.

I do not know what this questions wants because the Compton scattering equation takes 3 parameters(lambda, lambda', and theta) and they only give 1 here (lambde_blue light or lambda_X-rays). Anyone want to rephrase this for me?

Homework Equations

The Attempt at a Solution

 

[dextercioby]

I guess they mean the ratio $\Delta \lambda/ \lambda$, where \Delta \lambda =\lambda' -\lambda. But i don't know what you should do with the angle...