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# Cubic equation with a non-integer repeated root watch

1. Afternoon!

I was just wondering whether anyone could help me, I need an equation (preferably a cubic for simplicity) that has a non-integer repeated root, ie just touches the x axis.

Rather than just giving me one it would be nice to have a brief explanation of how I'd go about formulating one from scratch.

2. (Original post by Alex Bampton)
...
Rather than think about the cubic as x^3+..., think about it in terms of products of linear factors.

E.g.

If I wanted a quadratic with disparate roots, I'd go (x-1)(x-2) giving me....
3. (Original post by ghostwalker)
Rather than think about the cubic as x^3+..., think about it in terms of products of linear factors.

E.g.

If I wanted a quadratic with disparate roots, I'd go (x-1)(x-2) giving me....
Ah so is it as simple as expanding out something like (x-1.2876)(x-0.43)(x-0.88). That wasn't so bad!

How about if I were to go about finding an equation that has irrational roots?
4. (Original post by Alex Bampton)
Ah so is it as simple as expanding out something like (x-1.2876)(x-0.43)(x-0.88). That wasn't so bad!
Although none of those are repeated.

How about if I were to go about finding an equation that has irrational roots?

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