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Integrate a polynomial times powers of polynomials by raising each power by one - #1968

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a-polynomial-times-powers-of-polynomials-by-raising-the-powers
Oct 20, 2026
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P R_1^(s_1) ... R_m^(s_m), with an exponent that is a fraction or a symbol, is answered as Q R_1^(s_1 + 1) ... R_m^(s_m + 1) for a polynomial Q, where there is one. With R = R_1 ... R_m, the derivative of that is the integrand's powers times Q' R + Q sum_i (s_i + 1) R_i' R/R_i. Setting it equal to P is a linear system in the coefficients of Q; where the system has no solution, the rule declines.

For example, Rubi's (a g + e x - b g x^4)/(a + b x^4)^(3/2) is (2 a g x + e x^2)/(2 a sqrt(a + b x^4)). A symbolic power of a constant multiple of x, (c x)^t, is read as such beside it.

Measured on 8a1ef454, branch against master:

Run Problems Master Branch
Pocket: Rubi's 1.1 and 1.2 files it reaches, every third solved problem 3,198 3,132 solved 3,158 solved
Family 1, 40 a file 1,381 1,362 1,368
Family 0, whole 1,814 1,789 1,789
Families 2 to 8, sampled 2,410 2,362 2,362

Re-run alone on both builds, all 28 problems that moved answer on the branch, against 2 on master: 26 gained, across 1.1.1.3, 1.1.2.3, 1.1.3.2, 1.1.3.8, 1.2.1.3, 1.2.1.9, 1.2.2.5 and 1.2.3.5. None goes the other way. No run had a wrong answer.

APolynomialTimesPowersOfPolynomialsByRaisingThePowersIntegralTest differentiates the answers back. BREAKING-CHANGES.md has the entry, with the 2.5.0 column measured on v2.5.0.

Part of #233.

🤖 Generated with Claude Code

https://claude.ai/code/session_012sonx8iAspMiwRwokT1Ura

…wer by one

P R_1^(s_1) ... R_m^(s_m), with an exponent that is a fraction or a symbol, is
answered as Q R_1^(s_1 + 1) ... R_m^(s_m + 1) for a polynomial Q where there is
one. With R = R_1 ... R_m, the derivative of that is the integrand's powers
times Q' R + Q sum_i (s_i + 1) R_i' R/R_i, and setting it equal to P is a linear
system in the coefficients of Q. Rubi's (a g + e x - b g x^4)/(a + b x^4)^(3/2)
is (2 a g x + e x^2)/(2 a sqrt(a + b x^4)), and 25 more of Rubi's 1.1.x and
1.2.x of that shape were declined or ran past the budget. A symbolic power of
a constant multiple of x, (c x)^t, is read as such beside it.

Part of #233.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012sonx8iAspMiwRwokT1Ura
@Rafael-SOWNet Rafael-SOWNet added this to the 2.6.0 milestone Oct 20, 2026
@Rafael-SOWNet
Rafael-SOWNet merged commit 593c539 into master Oct 20, 2026
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@github-project-automation github-project-automation Bot moved this from Todo to Done in AngouriMath Oct 20, 2026
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