Response to project proposal feedback I have recently submitted a project proposal for the final project of one of my graduate courses.

The unit lecturer who marked my proposal is in his 70s and he has once stated in class that he's an engineer for so long that he knows everything better than us and there is very little that we can outsmart him. (Maybe not exactly with these words but something very similar.) Although I am not very comfortable with the way he said it, he is not entirely wrong as he is a well-known professor with a lot of experience.

He marked me down in 2 sections and his comments are quite controversial. 

The 1st section is the historical background of the product I have proposed. He is the history himself I give him that but my writing was based on a research and I didn't made up a random historical background. I even cited the books I have used while writing that section. The books that I have used are highly reputable in my field of study.

The 2nd section I got marked down is about the assumptions I made to simplify the design while running computer simulations. Mid/small scaled robot arms often use "servo" motors and these motors are capable of rotating 180 degrees and some can be modified to rotate 360 degrees. I have got several datasheets to verify this information. Yet, the lecturer commented "All servo motors rotate 360 degrees." which is clearly not the case.

I will email him to respond his comments but I sometimes have trouble with expressing my ideas without being annoying/impolite and hence I need your advice on how to structure my email. I don't want him to get annoyed and start picking up on me in the upcoming submissions.

I am a person who gets motivated by the marks I receive. At the beginning I was very excited about this project and the way my proposal was marked discouraged me. I don't think it received the mark I have deserved. Consequently,  I don't feel motivated anymore. Some of the proposal (from other students) are marked by the unit TA and he is a very fair guy. Although both the unit lecturer and the TA mark based on the same marking rubric, I bet I could get 10 more points if TA was marking me.
If you believe you have been unfairly graded, stick to the facts in writing to your professor. Don't argue &quot;I should get a higher grade.&quot; Instead, frame it as a question.

Dear Prof. X
I am confused about a couple of the comments you made in grading my paper.

On page A, you said &quot;B,&quot; but I found (cite literature supporting your claim).
[Repeat for each comment you'd like a response to.]

Could you please explain the discrepancy?
[Closings.]

This usually works better as a way of requesting a regrade than saying &quot;I deserve a higher grade because [reasons].&quot;