add trapezoid method to Integral.as_sum
add trapezoid method to Integral.as_sum

The function being integrated was simplified so the ouptput
could be more easily tracked. The docstring was condensed a
bit, too.

souravsingh/sympy,drufat/sympy,grevutiu-gabriel/sympy,Mitchkoens/sympy,Gadal/sympy,pandeyadarsh/sympy,ahhda/sympy,Titan-C/sympy,pandeyadarsh/sympy,cccfran/sympy,cswiercz/sympy,beni55/sympy,Titan-C/sympy,sunny94/temp,Vishluck/sympy,saurabhjn76/sympy,atreyv/sympy,Designist/sympy,meghana1995/sympy,yukoba/sympy,Designist/sympy,AunShiLord/sympy,kaushik94/sympy,wyom/sympy,shipci/sympy,sahilshekhawat/sympy,AkademieOlympia/sympy,dqnykamp/sympy,mcdaniel67/sympy,vipulroxx/sympy,rahuldan/sympy,jamesblunt/sympy,liangjiaxing/sympy,emon10005/sympy,hrashk/sympy,jamesblunt/sympy,Davidjohnwilson/sympy,pbrady/sympy,kumarkrishna/sympy,kumarkrishna/sympy,wanglongqi/sympy,kevalds51/sympy,jamesblunt/sympy,lidavidm/sympy,VaibhavAgarwalVA/sympy,AunShiLord/sympy,emon10005/sympy,sahmed95/sympy,hrashk/sympy,atsao72/sympy,MridulS/sympy,vipulroxx/sympy,shikil/sympy,kmacinnis/sympy,grevutiu-gabriel/sympy,sunny94/temp,shikil/sympy,asm666/sympy,amitjamadagni/sympy,skidzo/sympy,bukzor/sympy,Curious72/sympy,jbbskinny/sympy,shikil/sympy,sahilshekhawat/sympy,meghana1995/sympy,toolforger/sympy,drufat/sympy,kmacinnis/sympy,oliverlee/sympy,jbbskinny/sympy,asm666/sympy,moble/sympy,MechCoder/sympy,yukoba/sympy,kaichogami/sympy,iamutkarshtiwari/sympy,abloomston/sympy,saurabhjn76/sympy,debugger22/sympy,Arafatk/sympy,Titan-C/sympy,skidzo/sympy,postvakje/sympy,shipci/sympy,drufat/sympy,farhaanbukhsh/sympy,Shaswat27/sympy,iamutkarshtiwari/sympy,atsao72/sympy,Gadal/sympy,Shaswat27/sympy,aktech/sympy,kaushik94/sympy,VaibhavAgarwalVA/sympy,ChristinaZografou/sympy,madan96/sympy,abloomston/sympy,cswiercz/sympy,Vishluck/sympy,dqnykamp/sympy,chaffra/sympy,mafiya69/sympy,pbrady/sympy,sahmed95/sympy,lidavidm/sympy,abhiii5459/sympy,Designist/sympy,ChristinaZografou/sympy,hargup/sympy,kevalds51/sympy,debugger22/sympy,skidzo/sympy,MridulS/sympy,grevutiu-gabriel/sympy,yukoba/sympy,AunShiLord/sympy,asm666/sympy,wanglongqi/sympy,moble/sympy,maniteja123/sympy,maniteja123/sympy,sunny94/temp,yashsharan/sympy,liangjiaxing/sympy,sahilshekhawat/sympy,oliverlee/sympy,kaushik94/sympy,chaffra/sympy,MechCoder/sympy,Gadal/sympy,atreyv/sympy,AkademieOlympia/sympy,madan96/sympy,garvitr/sympy,kumarkrishna/sympy,emon10005/sympy,sahmed95/sympy,jaimahajan1997/sympy,amitjamadagni/sympy,saurabhjn76/sympy,Sumith1896/sympy,pandeyadarsh/sympy,MechCoder/sympy,rahuldan/sympy,ahhda/sympy,Davidjohnwilson/sympy,chaffra/sympy,oliverlee/sympy,abhiii5459/sympy,cswiercz/sympy,iamutkarshtiwari/sympy,meghana1995/sympy,MridulS/sympy,liangjiaxing/sympy,Vishluck/sympy,cccfran/sympy,bukzor/sympy,jerli/sympy,dqnykamp/sympy,lindsayad/sympy,garvitr/sympy,Curious72/sympy,yashsharan/sympy,souravsingh/sympy,Curious72/sympy,yashsharan/sympy,abhiii5459/sympy,wyom/sympy,mafiya69/sympy,hargup/sympy,aktech/sympy,ga7g08/sympy,Mitchkoens/sympy,jbbskinny/sympy,hrashk/sympy,postvakje/sympy,cccfran/sympy,ga7g08/sympy,beni55/sympy,jaimahajan1997/sympy,mafiya69/sympy,jaimahajan1997/sympy,kaichogami/sympy,madan96/sympy,sampadsaha5/sympy,beni55/sympy,souravsingh/sympy,Arafatk/sympy,rahuldan/sympy,debugger22/sympy,toolforger/sympy,farhaanbukhsh/sympy,abloomston/sympy,wanglongqi/sympy,aktech/sympy,postvakje/sympy,Mitchkoens/sympy,atreyv/sympy,Sumith1896/sympy,moble/sympy,lindsayad/sympy,kmacinnis/sympy,pbrady/sympy,toolforger/sympy,jerli/sympy,Shaswat27/sympy,jerli/sympy,lidavidm/sympy,ChristinaZografou/sympy,shipci/sympy,sampadsaha5/sympy,mcdaniel67/sympy,Arafatk/sympy,maniteja123/sympy,bukzor/sympy,vipulroxx/sympy,garvitr/sympy,kevalds51/sympy,farhaanbukhsh/sympy,ga7g08/sympy,hargup/sympy,wyom/sympy,VaibhavAgarwalVA/sympy,AkademieOlympia/sympy,diofant/diofant,ahhda/sympy,lindsayad/sympy,atsao72/sympy,mcdaniel67/sympy,Sumith1896/sympy,sampadsaha5/sympy,skirpichev/omg,Davidjohnwilson/sympy,kaichogami/sympy