[Expired]Texas Instruments TI-84 Plus CE Color Graphing Calculator

: I remember the school store offers rentals? About $10 or $20 per semester? 我记得学校store可以租？一学期大概10还是20刀？

: Better to buy second-hand on FB Marketplace FB marketplace 买二手的好点

: Learned it just last semester, but now I can't use this calculator anymore. 上学期才学完，现在这计算器已经不会用了

: Being a poor student, I still didn't understand when the teacher taught it in class back then. 学渣的我 当年老师课堂上教 我仍然不会

: Let's review some common first derivatives together: y = ax + b,  y' = a y = ax^n,   y' = anx^(n-1) y = sinx,   y' = cosx y = cosx,   y' = -sinx y = tanx,   y' = (secx)^2 y = e^x,    y' = e^x y = lnx,    y' = 1/x 大家来和我一起复习一下常见一阶导数： y=ax+b, y'=a y=ax^n, y'=anx^(n-1) y=sinx, y'=cosx y=cosx, y'=-sinx y=tanx, y'=(secx)^2 y=e^x, y'=e^x y=lnx, y'=1/x

: Way, way back when I was a student, there was nothing like this. 好久好久以前我当学生的时候哪有这个

: Sin, cos... These memories are painful yet full of joy. So many years have passed. Sin cosin ….. 这回忆痛并快乐着 多年过去了。

: Calculus course... 微积分课程。。

: College nightmare college噩梦

: Can it be used in exams?? 考试能带？？

: Wow, this is amazing 哇 这个厉害了

: Calculators have evolved so much, I totally can't understand what they are anymore...😓 计算器已经进化到我完全看不懂的样子了...😓