Paul's Notes remains the absolute best textbook Calculus and intro to DiffEQ! Not sure if it's been updated since 2005, but I mean, it's not like they're discov

Paul's Notes remains the absolute best textbook Calculus and intro to DiffEQ! Not sure if it's been updated since 2005, but I mean, it's not like they're discovering new Calc II methods! Being that it's not a $200 textbook rehashing the same stuff as the last 10 editions, it's easily one of my favorite websites