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Re: Help me please!!!


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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>       <---------------- at ----------------->


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


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