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SolveAHalfOddPowerOfALinearPlusTheRootOfAQuadraticByEulersSubstitution​(AngouriMath.​Entity,​AngouriMath.​Entity.​Variable,​System.​Boolean)

 Method (no overloads)

Summary

A rational function of x and R = sqrt(Q) beside a half-odd power of
L + R, for a quadratic Q and a linear L with Q - L^2 = c (x - r)^2,
in Euler's u = (R - L)/(x - r): x - r = 2 l u/D, R = L + u (x - r) and
L + R = 2 c l/D, for l = L(r), D = c - 2 b u - u^2 and b the slope
of L, so that the integrand is rational in u beside a half-odd power of the
quadratic D. Bondarenko's sqrt(1 + sqrt(x) + sqrt(1 + 2x + 2 sqrt(x))) is
8 sqrt(2) u (1 + u^2)/D^(7/2) under x = t^2.

Remarks

With s = x - r, R^2 = L^2 + c s^2 and R = L + u s give
s (c - 2 b u - u^2) = 2 l u, (L + R)(R - L) = c s^2 gives L + R = c s/u,
and dx = 2 l (c + u^2)/D^2 du. The power (L + R)^(k/2) is asked as
(2 c l)^(k/2)/D^(k/2), which it is up to a sign, and the answer in u is
multiplied by the quotient of the two, whose square is one: it holds on every branch.
Declined before, since no substitution any rule tries makes the nested root rational.
The answer is differentiated back at sampled points.
https://github.com/asc-community/AngouriMath/issues/233

























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