# Math Help - [SOLVED] Find f '(x) and f '' (x)

1. ## [SOLVED] Find f '(x) and f '' (x)

Find f '(x) and f '' (x)

I believe this states find f prime and f double prime.

f(x) = x / 3 + e^(x)

Okay so I know that the derivative of e ^(x) is e^x
and that the derivative of x is 0 right?
Okay and I'm going to use the quotient rule:

f(x) / g(x) = [ g(x)f '(x) - f(x) g' g(x) ] / [ (g(x))^(2) ]

2. Originally Posted by moonman
Find f '(x) and f '' (x)

I believe this states find f prime and f double prime.

f(x) = x / 3 + e^(x)

Okay so I know that the derivative of e ^(x) is e^x
and that the derivative of x is 0 right?
Okay and I'm going to use the quotient rule:

f(x) / g(x) = [ g(x)f '(x) - f(x) g' g(x) ] / [ (g(x))^(2) ]
$\frac{d}{dx}(x)=1$

$f'(x)=\frac{(3+e^{x})\cdot 1-x(e^{x})}{(3+e^{x})^2}=\frac{x+(1-x)e^{x}}{(3+e^{x})^2}$