Question

Hey guys ,I wanted to ask:

given this function : x+ 1/x

if I wanted to find the local max and local min , I'll find the critical number first which is : x=0

but how could I find the local max and min if it's undefined ?

Answer 1

by the way it's not x+1/x ,,, it's x .... + 1/x

Answer 2

f(x)=x+1/x
find f'
then find roots of f'=0
the determine the sign of f' in table

Answer 3

First of all it's x + ... 1/x , second of all I did find the derivative which is 1 ... -1/x^2

So we'll get the undefined parts now , which will be x=0

but if I plugged this into the original function It would be undefined because 0+1/0 is undefined , but how could I know which is max which is min without seeing where it's inc and dec.