# Simple derivative

1. Mar 30, 2009

### nameVoid

D= (x^2+x)^(1/2)

Why does the chain rule in this case produce D' = (1/2)(x^2+x)^(-1/2) (2x+1)(x')

and not D' = (1/2)(x^2+x)^(-1/2) (2x+1)(2x')

2. Mar 30, 2009

### rock.freak667

$$\frac{dD}{dt}=\frac{dx}{dt} \times \frac{dD}{dx}$$

So like in the other thread, can you understand why now?