1. ## Inflection points

Find the inflection points of f(x)=x/(5x^2+5)^2

List the x-values:

I found f''(x) which is f''(x)= 10x/(5x^2+5)^2

I get 0, but this answer is wrong on my online hw

thanks

2. Originally Posted by Asuhuman18
Find the inflection points of f(x)=x/(5x^2+5)^2

List the x-values:

I found f''(x) which is f''(x)= 10x/(5x^2+5)^2

I get 0, but this answer is wrong on my online hw

thanks
I've got a different second derivative. And consequently 3 zeros of f''(x).

Spoiler:
$\displaystyle f'(x)=\dfrac{1-3x^2}{5(x^2+1)^4}$
and
$\displaystyle f''(x)=\dfrac{12x(x^2 - 1)}{25(x^2+1)^3}$