Lesson Comments

f zhe4ge han2shu4 zai4 3 de dao3shu4 deng3yu2 h qu1jin1yu2 0 de shi2hou4 (or you can just say "shi2" here ) de ji2xian4 deng3yu2 (3 jia1 h) ping2fang1... Read more

I can see Sealand from my bedroom window here in Felixstowe. Read more

I have always used f'(x²) and (d/dx)(x²) interchangeably. To me the prime on the f'(x²) makes it the derivative and it represents the same thing. Gra... Read more

Enjoy the stares and embrace your different appearance. It certainly helps when it comes to free beer in bars. Read more

Here is an attempt at the translation. (I had help) f 这个函数在 3 的导数等于 h 趋近于0 的时候 的极限 等于 （3加h）的平方减去3的平方 整体除以h 等于 9 加 6h 加 h 平房 减 9 整体除以 h... Read more

Hi Bodawei some folks just aren't as enlightened as you are. They have to be informed first--not even reminded--of that fact you say is so mundane a... Read more

Is it just me, or did anyone else find this dialogue quite a challenge to understand?  The speed of delivery was much faster than other intermedi... Read more

I believe the only way to declare a level is by the level of lessons you subscribe to. There used to be a level choice within profile but that is gone... Read more

In this same page where it says Lesson Review Downloads you can download MP3 of this lesson and pdf/text of the vocabulary Read more

What you say is true, but it is not f'(x^2). it is (d/dx)(x^2) or f'(3) where f(x)=x^2, f'(x^2)=2(x^2). because, as you say, you first di... Read more