Given the limit, find F and A?

[xzh]

This limit represents the derivative of some function F at some number A.
lim___________ ([4th root (16+h)] - 2)
_____________________________________
h->0_________________h

f = ?
a = ?

I don't know how to solve this? Teacher said it is going to be on midterms but he never went through it. Thanks.

I think a = 0

 

[losiu99]

How about f (x) = x^1/4, a = 16?

 

[xzh]

hmm, how did you get this? thanks!

How about f (x) = x^1/4, a = 16?

 

[Office_Shredder]

You should start by writing down the definition of the derivative and comparing it to the given limit. You can find the f(a+h) term by looking at where (_+h)'s occur in the given limit