Question

Find the absolute maximum and absolute minimum values of f(x)=x−lnx on the interval [1/8,8].

Answer 1

I get f '(x)= 1-(1/x)
and a critical point of x=0
When I evaluate f at the critical point and end points I get f(0) as DNE
I get f(8)= 5.920558
f(1/8) = 2.20444
I thought these would be the absolute maximum and minimum, but apparently their not

Answer 2

i tell you the method

Answer 3

for critical point put f'(x)=0
1-1/x=0
x-1=0
x=1
is critical point thats the mistake you have done

Answer 4

can u get it?

Answer 5

oh! thank you!!

Answer 6

welcome