4 ms·

I wouldn't describe it as a useless trick to know that sin(2x) ≈ 2x for small x. I'd describe this as a basic part of understanding what it means to say sin'(0)

I wouldn't describe it as a useless trick to know that sin(2x) ≈ 2x for small x. I'd describe this as a basic part of understanding what it means to say sin'(0) = 1.

sokoloff 4y ago
> sin'(0) = 1. = 0, not 1, unless I'm misunderstanding your notation (or blowing trig).
- MikeDelta 4y ago
  The ' stands for (first-order) derivative. The second would be '' and so on. sin(0)=0, sin'(0)=1
  - sokoloff 4y ago
    Ah, thanks! I was thinking it was inverse (or typo); didn’t get to d sin(x)/x.