# Math Help - Second Derivative

1. ## Second Derivative

What is the second derivitive of f(x)=x-4/3x+2
I have the first derivitive, which is f'(x)=-10/(3x+2)^2
If that's right, then what is the second derivitive... I'm sketching graphs for ap cal

2. You pretty much do what you did to get the first derivative again

$f'(x)\frac{-10}{(3x+2)^2}
$

into

$\frac{(3x-2)^2-(2)(3x+2)(3)(-10)}{(3x+2)^3}$

I think I did that right hahaha. Basically you take the denominator into the numerator and use the chain rule again and get all that goobley gook up there just use your $\frac{h(x)g'(x)-h'(x)g(x)}{h(x)^2}$ formula again. This of course creates steps that can sort of have you making mistakes here and there so make sure to double check you work and plot a few points

3. Thing is I have to use the fricken quotient rule.
So that is what's going on there... Lol and how are you using the fancy text? /jealousy.

4. I know how you feel. I dread division as it adds more steps into the process and I worry I'm going to gunk stuff up somewhere.

The "fancy text" is a forum function. When replying there's a Sigma symbol at the top (looks like a funky looking E thing) and it'll create "math brackets" you than do your formula in there. There are certain codes with some problems like division problems are written "/frac {}{}" with the variables in the numerator in the first {} and denominator in the second{}. I'm sure someone can direct you to a tutorial or FAQ that has it somewhere around here hahaha. I'm sort of new

5. Originally Posted by Muhammed Ali
What is the second derivitive of f(x)=x-4/3x+2
I have the first derivitive, which is f'(x)=-10/(3x+2)^2
If that's right, then what is the second derivitive... I'm sketching graphs for ap cal
The question has been more or less asked (and very well answered) here.