<p>so, i got a D+ in calculus my junior year, second semester. in every college application, in the additional information section, i've explained why. however, do i still need to send another letter to my colleges explaining why i got that grade?</p>
<p>No. Colleges will have read your explanation in the additional info section, so does it really make sense to send them another letter saying the same thing? You never needed to explain why you got a D in the first place, anyway.</p>