This is a great assignment. Both of these photographs capture the effects of what this assignment asked for. Your first photograph showcases your understanding of hard lighting, while your second photograph uses much softer lighting.
Let’s look at the hard lighting photograph. Your composition is very good. All of the important details are in the photograph. You’ve also used a shallow depth of filed to help isolate your main subject out of the background.
My only concern with this photograph is that you have some “blow out” areas in the subjects forehead. Most digital cameras have a narrow latitude and therefore details in the bright white areas are lost. Areas that are “blow out” are technically missing information. This cannot be recovered in post production. To learn more about dynamic range and latitude read our blog post here
http://photographyicon.com/blog/2008/11/26/digital-cameras-latitude-dynamic-range/
Your second photograph is also great in terms of composition and the photograph doesn’t suffer from any loss of detail due to harsh lighting. Great work.