# D3y/dx3 OF Y= 1/X+1

1. Nov 11, 2007

### mo7tn

1. The problem statement, all variables and given/known data
d3y/dx3 OF Y= 1/X+1

2. Relevant equations

Y= 1/X+1

3. The attempt at a solution

i TRIED USING THE QUOTIENT RULE BUT BECAME STUCK AFTER DOING- (X+1)D/DX(1) + (1)D/DX(X+1)= (X+1)(1)+(1)(1)=1+1+1= 3 BUT HOW DO GET TO THE THRID DEGREE IM LOST

2. Nov 11, 2007

### rock.freak667

$$y=\frac{1}{x+1}$$

$$\frac{dy}{dx}=\frac{1(x+1)-1(1)}{(x+1)^2}$$

$$\frac{dy}{dx}==\frac{x}{(x+1)^2}$$
then just differentiate that twice again and you'll get $\frac{d^3y}{dx^3}$