Cannot Factor an expression
- To: mathgroup at smc.vnet.net
- Subject: [mg87563] Cannot Factor an expression
- From: Francogrex <franco at grex.org>
- Date: Sun, 13 Apr 2008 03:31:17 -0400 (EDT)
If Factor is effectively the reverse of expand, then how come factor cannot find back the expression below? Expand[Sum[(Subscript[z, i] - 1)*(\[Mu] - Subscript[x, i])^2, {i, 1, 3}]] Factor[-3*\[Mu]^2 + 2*\[Mu]*Subscript[x, 1] - Subscript[x, 1]^2 + 2*\[Mu]*Subscript[x, 2] - Subscript[x, 2]^2 + 2*\[Mu]*Subscript[x, 3] - Subscript[x, 3]^2 + \[Mu]^2*Subscript[z, 1] - 2*\[Mu]*Subscript[x, 1]*Subscript[z, 1] + Subscript[x, 1]^2* Subscript[z, 1] + \[Mu]^2*Subscript[z, 2] - 2*\[Mu]*Subscript[x, 2]*Subscript[z, 2] + Subscript[x, 2]^2* Subscript[z, 2] + \[Mu]^2*Subscript[z, 3] - 2*\[Mu]*Subscript[x, 3]*Subscript[z, 3] + Subscript[x, 3]^2* Subscript[z, 3]] Is there some additional arguments to the function factor so that it can find back the original: Sum[(Subscript[z, i] - 1)*(\[Mu] - Subscript[x, i])^2, {i, 1, 3}] Thanks for help with this
- Follow-Ups:
- Re: Cannot Factor an expression
- From: Andrzej Kozlowski <akoz@mimuw.edu.pl>
- Re: Cannot Factor an expression