Re: Cancel order
- To: mathgroup at smc.vnet.net
- Subject: [mg123266] Re: Cancel order
- From: Andrzej Kozlowski <akoz at mimuw.edu.pl>
- Date: Tue, 29 Nov 2011 07:40:59 -0500 (EST)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- References: <201111291205.HAA05469@smc.vnet.net>
On 29 Nov 2011, at 13:05, =E9=81=93 =E5=8E=9A wrote:
> How can I make Sqrt[(v1^2+v2^2)(g^2+gp^2)]/Sqrt[v1^2+v2^2] simple in
> mathematica?
>
You need the assumption that the expressions under the square root are positive. So:
Assuming[g^2 + gp^2 >= 0 && v1^2 + v2^2 > 0,
Simplify[Sqrt[(g^2 + gp^2)*(v1^2 + v2^2)]/Sqrt[v1^2 + v2^2]]]
Sqrt[g^2 + gp^2]
In particular, this will be true if everything in your expression is real:
Assuming[Element[_, Reals],
Simplify[Sqrt[(g^2 + gp^2)*(v1^2 + v2^2)]/
Sqrt[v1^2 + v2^2]]]
Sqrt[g^2 + gp^2]
Andrzej Kozlowski
- References:
- Cancel order
- From: é å <shlwell1988@gmail.com>
- Cancel order