Coefficient

*To*: mathgroup at yoda.ncsa.uiuc.edu*Subject*: Coefficient*From*: cfcgf at ux1.cts.eiu.edu (Chuck Fleming)*Date*: Sun, 9 Dec 90 10:43:06 CST

> I seem to be having a problem with the behaviour of Coefficient[] in > Mathematica, namely if I have a series such as > > sum = ... + a n + b + c/n +.... > > then Coefficient[sum,n] gives a, Coefficient[sum,1/n] gives c, but > Coefficient[sum,1] does NOT give b, but zero instead! This is causing me > problems, and I cannot see a simple work-around. You might break up sum into two sums. One with nonnegative powers of n and one with negative powers of n. Then Coefficient[posSum, n, i] will give the coefficient of n^i including i=0. chuck fleming