Princeton Review Question
Posted: Thu Sep 18, 2008 6:11 pm
On page 93, number 11 of the 3rd edition,
If f(x) is a function that is differentiable everywhere, what's the value of this limit?
lim h->0 {f(x+3h^2)-f(x-h^2)}/2h^2
The answer given in the book is 2f'(x), but when I let f(x)=x^2, I get 2x+4h^2, so when h goes to zero, I get 2x, which obviously is f'(x) not 2f'(x).
I get the same answer (f'(x)) when I let f(x)=x. Anyone know what is going on here? Am I making a simple mistake, or is it another princeton typo?
Also, anyone smarter than me know how to create a list that anyone can add to, to list princeton typos? I saw a string regarding this but it only covered the first few. I have a couple to add already, and expect several more.
Thanks for the halp.
If f(x) is a function that is differentiable everywhere, what's the value of this limit?
lim h->0 {f(x+3h^2)-f(x-h^2)}/2h^2
The answer given in the book is 2f'(x), but when I let f(x)=x^2, I get 2x+4h^2, so when h goes to zero, I get 2x, which obviously is f'(x) not 2f'(x).
I get the same answer (f'(x)) when I let f(x)=x. Anyone know what is going on here? Am I making a simple mistake, or is it another princeton typo?
Also, anyone smarter than me know how to create a list that anyone can add to, to list princeton typos? I saw a string regarding this but it only covered the first few. I have a couple to add already, and expect several more.
Thanks for the halp.