Re: Integrating a Piecewise function four times but different results

*To*: mathgroup at smc.vnet.net*Subject*: [mg121787] Re: Integrating a Piecewise function four times but different results*From*: Gabriel Landi <gtlandi at gmail.com>*Date*: Sun, 2 Oct 2011 02:36:25 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*References*: <201110010708.DAA17775@smc.vnet.net>

This really seems like a bug. T he problem is on the integration of p2. If you first do the integration of p1 first and then substitute the values you get the correct answer. soln2[x_] = Integrate[Integrate[Integrate[Integrate[p1[x], x], x], x], x] + r*x^3 + s*x^2 + u*x + v /. wmax -> 1 /. L -> 1 Moreover, it gives the wrong answer because the function is defined piecewise. For instance, Integrate[Integrate[Integrate[Integrate[2 (1 - x), x], x], x], x] obviously gives the correct result.

**References**:**Integrating a Piecewise function four times but different results***From:*"Rob Y. H. Chai" <yhchai@ucdavis.edu>