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**slevvio** Hello,

Let $\displaystyle k$ be a field of characteristic 2. Then find the ideal of $\displaystyle X = V(t_1^2 + t_2^2 + t_3^2) \subseteq \mathbb{A}_k^3$.

I'm not sure how to solve this. I mean, since $\displaystyle k$ is of characteristic two, I can see that$\displaystyle (t_1 + t_2 + t_3)^2 = t_1^1 + t_2^2+t_3^2$, so that $\displaystyle I_X = \sqrt{\langle(t_1 + t_2 + t_3)^2\rangle}$. Is it just what we'd think it would be, i.e. $\displaystyle I_X = \langle t_1 + t_2 + t_3 \rangle$ ? If so, why is it true? But how do I find this radical ideal? And is this the best way to work out what the ideal is?

Thanks for any help