Hi, I have this question that suppose to use Method of Differences to solve it.(adsbygoogle = window.adsbygoogle || []).push({});

By using the method of differences, find the sum of the first n terms of the series whose r^{th}term, u_{r}, are

U_{r}= (2r - 1)/r(r+1)(r+2)

I used partial fraction and found.

U_{r}= -1/(2r) + 3/(r+1) - 5/[2(r+2)]

then i did

-(1/2)[5/(r+2) - 6/(r+1)] - 1/(2r)

-(1/2)[5/(n+2) - 5/2] - (1/2)(1/r)

5/4 - 5/(2n+4) - (1/2)[1/(1/2)(n)(n+1)]

(10n + 20 - 20)/4(2n+4) - 1/(n)(n+1)

But the answer is wrong. Any help?

Thanks.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Method of Differences problem

**Physics Forums | Science Articles, Homework Help, Discussion**