- #1
opticaltempest
- 135
- 0
I have the function [tex] \[y = \sqrt x - 4\ln (x)\][/tex]
I find the derivative to be [tex] \[y' = \frac{{\sqrt x - 8}}{{2x}}\] [/tex]
When finding the critical numbers of y' I look for where the derivative
is equal to zero or where the derivative is undefined. So where y' is
equal to zero is when x=64. y' is undefined when x=0, but when x=0
the original function is also undefined. Since x=0 makes the original
function undefined can I exclude it from my critical points? I am thinking
I am able to since x=0 isn't even in the domain of y.
Thanks
I find the derivative to be [tex] \[y' = \frac{{\sqrt x - 8}}{{2x}}\] [/tex]
When finding the critical numbers of y' I look for where the derivative
is equal to zero or where the derivative is undefined. So where y' is
equal to zero is when x=64. y' is undefined when x=0, but when x=0
the original function is also undefined. Since x=0 makes the original
function undefined can I exclude it from my critical points? I am thinking
I am able to since x=0 isn't even in the domain of y.
Thanks