If the electric potential in a region is given by V(x)=6/x2, the x component of the electric field in that region is? ... I'm not sure if it's −12x^(−3) or 12x^(-3). The given formula is Ex=-dV/dx but an example in the book doesn't multiply with the minus. (all help is really well appreciated)

Question

If the electric potential in a region is given by V(x)=6/x2, the x component of the electric field in that region is?  ... I'm not sure if it's −12x^(−3)  or 12x^(-3). The given formula is Ex=-dV/dx but an example in the book doesn't multiply with the minus. (all help is really well appreciated)

irishboy123 · Answer

convention has [we are in 1d here, i think]:

$\mathbf{E(x)} = - \dfrac{d}{dx}  V(x)$

so if $ \large V(x)=\frac{6}{x^2}$, then $\large -\frac{dV}{dx}$ might just come out as you expect it might.