Update finite_diff.py
Update finite_diff.py

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