What are the critical numbers of the function f(x) = x*sqrt2x+1?

[npellegrino]

Find all critical numbers if any.

I found the critical number -1/3 , just checking my work. Any input would be great.

the function f(x) = x*sqrt2x+1
f'(x) = (3x+1)/sqrt2x+1

3x+1 = 0 , x = -1/3

 

[Dustinsfl]

I just ansered this question here
http://www.mathhelpforum.com/math-help/calculus/136999-critical-numbers.html

 

[npellegrino]

Critical numbers are -1/3 and -1/2