I am studying for a test and i can't figure out for the life of me how my book derived the solution for this problem I know it has to be basic i just dont see it...(adsbygoogle = window.adsbygoogle || []).push({});

An electric dipole consists of two charges of equal magnitude and opposite sign separated by a distance 2a... The dipole is along the x axis and is centered at the origin.

calculate V and Ex if point P is located anywhere between the two charges.

I understand the concept of this, and have calculated V, which is [ (2*(Ke)*q*x) / ((a^2) - (x^2)) ] and i know how to start the problem of Ex...

Ex = - (dV/dx) = - [ (2*(Ke)*q*x) / ( (a^2) - (x^2) ) ....

But I can't remember or figure out for the life of me how they got

= - 2*(Ke)*q * [ { (a^2) + (x^2) } / { ( (a^2)-(x^2) )^2 } ]

Can Anyone please help? :D

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# Derivation of the electric field from the potential

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