A rod of length L lies along the x axis with its left end at the origin and has a nonuniform charge density @ = &x. What is the electic potential a distance d from the origin?(adsbygoogle = window.adsbygoogle || []).push({});

V = k int dQ/x where:

dQ = &x dx so:

V = k& int (x/x+d)dx from (0 to L)

I let u = x+d and x = u-d

so:

V = k& int (1 - d/u)du = (x+d) - dln(x+d) (0 to L)

and I get: V = k&[L + dln(1 + d/L)]

in the book the answer is: k&[L - dln(1 + L/d)]

what am I doing wrong?

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# Electric potential

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