Re: express a quadratic, in the form (x+a)^2 + b
- To: mathgroup at smc.vnet.net
- Subject: [mg84363] Re: express a quadratic, in the form (x+a)^2 + b
- From: Adriano Pascoletti <adriano.pascoletti at gmail.com>
- Date: Thu, 20 Dec 2007 00:09:24 -0500 (EST)
- References: <fkan3b$d6k$1@smc.vnet.net>
On Dec 19, 10:08 am, "Joseph Fagan" <noemailple... at nowhere.ru> wrote:
> I'm a Mathematica beginner.
> I wish to express a quadratic, in the form (x+a)^2 + b
> eg to express x^2 + 4x + 7 as (x+2)^2 + 3
> Is there an easy way?
> Thanks
> Joe
Take the Taylor expansion near the coefficient of x divided by 2:
(Normal[Series[#1, {x, -Coefficient[#1, x, 1]/2, 2}]] & )[x^2 + 4*x +
7]
gives 3 + (2 + x)^2.
Adriano Pascoletti