Re: Help me please!!!
- To: mathgroup at smc.vnet.net
- Subject: [mg5801] Re: [mg5770] Help me please!!!
- From: Dave Snead <dsnead at pacbell.net>
- Date: Wed, 22 Jan 1997 00:44:10 -0500
- Organization: Saguaro Software
- Sender: owner-wri-mathgroup at wolfram.com
Cyberman wrote:
>
> Hello. I've a little problem:
>
> I must invert this function: y = (x^2) + x for x >= 0
>
> Is there anybody that could help me?
>
> Thanx.
>
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Use Solve
In[7]:=Solve[y == (x^2) + x,x]
Out[7]:={{x -> (-1 - Sqrt[1 + 4*y])/2},
{x -> (-1 + Sqrt[1 + 4*y])/2}}
Use the 2nd solution, since y >= 0 gives x >= 0.
Dave Snead
dsnead at pacbell.net