David O.

Amateur mathematician, unfortunately with non-mathematical day job (addendum: but luckily now retired!).


514,677 students helped

Level 6 in Algebra Level 4 in Precalculus Level 4 in Calculus Level 3 in Trigonometry Level 2 in Statistics Level 2 in Physics Level 1 in Prealgebra Level 1 in Socratic Meta