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 Author Comment/Response J H Ettle 07/02/03 05:08am I've been trying to take a derivative of a (general) summation (like the kind found in the attached notebook) with a symbolic upper limit. The derivative is with respect to a parameter that is passed to a function F inside the sum. I then multiply the summand by a function L of the index to get: Sum[L[i] F[s], {i, 1, M}]. I then take the derivative of the above with respect to s. Mathematica passes the derivative into the sum, a-la Sum[D[L[i] F[s], s], {i, 1, M}], but doesn't carry the derivation on through. I have to manually extract the summand and evaluate it to get L[i] F'[s], as expected. Why is this? And how come Mathematica DOES carry the differentiation through when I try the same with an analogous integral? Attachment: DerivativeAnomaly.nb, URL: ,

 Subject (listing for 'Taking Derivative inside Sum') Author Date Posted Taking Derivative inside Sum J H Ettle 07/02/03 05:08am Re: Taking Derivative inside Sum Forum Modera... 08/03/03 4:57pm
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