Re: Solve equation with summation?
- To: mathgroup at smc.vnet.net
- Subject: [mg122992] Re: Solve equation with summation?
- From: Bob Hanlon <hanlonr357 at gmail.com>
- Date: Sat, 19 Nov 2011 06:48:31 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <ja5f56$69e$1@smc.vnet.net>
Not with my version
$Version
"8.0 for Mac OS X x86 (64-bit) (October 5, 2011)"
Solve[Sum[Subscript[a, i], {i, 1, n}]/x == 1, x]
{{x -> Sum[Subscript[a, i], {i, 1, n}]}}
Solve[Sum[Subscript[a, i]/x, {i, 1, n}] == 1, x]
{}
Bob Hanlon
On Fri, Nov 18, 2011 at 7:50 AM, Dr. Wolfgang Hintze <weh at snafu.de> wrote:
> Sorry, but with me both expressions (exactly copied from your message)
> give the same result.
> Regards,
> Wolfgang
>
> "Ivan" <iveney at gmail.com> schrieb im Newsbeitrag
> news:ja5f56$69e$1 at smc.vnet.net...
>> For a summation like \sum_{i=1}^n a_i/x = 1,
>>
>> Solve[Sum[Subscript[a, i], {i, 1, n}]/x == 1, x]
>>
>> gives a correct solution.
>>
>> However, by putting x into the summation:
>>
>> Solve[Sum[Subscript[a, i]/x, {i, 1, n}] == 1, x]
>>
>>
>> gives an empty set, why?
>>