Upwards trend in math grades

During my Freshman year, I got a B+ in Honors Algebra II, but I got an A in Honors Precalc the next year and an A+ in Calc BC this year. Would an upward trend like this (along with strong math SAT) eliminate any doubts about the first grade, or am I still at a minor disadvantage because of it? I know it’s probably not that big of a deal, but I would imagine that at MIT of all places you’d want your math to be as strong as possible.

It’s just not that big a deal. If you get rejected from MIT, it will not be because of a B+, IMO.