MathGroup Archive: February 2013 [00246]

[Date Index] [Thread Index] [Author Index]

ComplexExpand off by a factor of (-1)?

To: mathgroup at smc.vnet.net
Subject: [mg129882] ComplexExpand off by a factor of (-1)?
From: charles.ces at gmail.com
Date: Fri, 22 Feb 2013 01:05:24 -0500 (EST)
Delivered-to: l-mathgroup@mail-archive0.wolfram.com
Delivered-to: l-mathgroup@wolfram.com
Delivered-to: mathgroup-newout@smc.vnet.net
Delivered-to: mathgroup-newsend@smc.vnet.net

Would someone be able to help me understand why when I enter the expression:

ComplexExpand[(E^(I*y) - E^(-I*y))/2*I] I get a result of -Sin[y] instead of Sin[y]?

Thanks.

Charles S.

Follow-Ups:
- Re: ComplexExpand off by a factor of (-1)?
  - From: Raul Martinez <raulmart@mac.com>
- Re: ComplexExpand off by a factor of (-1)?
  - From: Murray Eisenberg <murray@math.umass.edu>
- Re: ComplexExpand off by a factor of (-1)?
  - From: Bob Hanlon <hanlonr357@gmail.com>

Prev by Date: Re: Is there a way to integrate and differentiate Erfi?

Next by Date: barchart

Previous by thread: Re: Is there a way to integrate and differentiate Erfi?

Next by thread: Re: ComplexExpand off by a factor of (-1)?