I'm trying to work out the method of getting the inverse function of(adsbygoogle = window.adsbygoogle || []).push({});

[itex] f(x) = x^2 + x [/itex]

I already know the inverse but I would like to know the method used to obtain it. So far I have:

Made f(x) = y:

[itex]y = x^2+2[/itex]

And then made y = x and x = y:

[itex]x=y^2+y[/itex]

And then I did this but I'm not sure if it's correct:

[itex]x=y(y+1)[/itex]

Apparently the solution is this

[itex]x(y) = 1/2 (-1±sqrt(4 y+1))[/itex]

But I need to know the steps to get that. Hope you can help. :)

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# Homework Help: The Inverse Function of f(x)=x^2+x

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