maximum-minimum?

Question

For f(x) = x8 /9 -x17 /9 find the critical numbers.


Solution:
Since f¢(x)= ---------- we see that f¢(x)=0 if x= ------- and that f¢( --------) does not exist.

Therefore, the critical numbers are --------- and ----------

Answer 1

To find critical vlues you differentiate the functionf first...
In this case after differentiating gives a whole number
i.e., 8/9 - 17/9 = -1.

then use f'(x) = 0 to get the answer...

here, -1 = 0.... which is absurd...
just make sure your question is correct...

Answer 2

I assume f¢(x) = the derivative of f(x). Peculiar notation!
Since f¢(x) = x^9 - 2x^18 we see that f¢(x)=0 if x= 0 or (1/2)^1/9 and that f¢( --------) does not exist.

Therefore, the critical numbers are 0 and (1/2)^1/9 .