# What is the second derivative of f(x)=ln (x+3)?

##### 2 Answers

Apr 25, 2018

#### Explanation:

NOTE that the **Derivative of #ln(x) = 1/x# and derivative of #1/x = -1/x^2#**

Apr 25, 2018

#### Explanation:

#"differentiate using the "color(blue)"chain rule"#

#"Given "y=f(g(x))" then"#

#dy/dx=f'(g(x))xxg'(x)larrcolor(blue)"chain rule"#

#rArrf'(x)=1/(x+3)xxd/dx(x+3)=1/(x+3)=(x+3)^-1#

#"differentiate "f'(x)" using the chain rule"#

#rArrf''(x)=-(x+3)^-2xxd/dx(x+3)=-1/(x+3)^2#