Hacker News Reader

I've seen pretty bright seeming UK university applicants able to do whatever you ask them but then completely shit the bed when you ask them to differentiate e^y with respect to y rather than e^x with respect to x.

View on HN

Even worse, I've seen a lot of people that where convinced the derivative of f(x)=e^7 is e^7

That would trick me too... Exam questions never ask 'trick' questions like that where the answer is zero/infinity/undefined.

I genuinely don't know whether the trick of that question is swapping the `e^x` with `e^y`, so just renaming a variable – or is `y` a function?

You're differentiating the function f(y) = e^y with respect to y

Reply on news.ycombinator.com