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Algebra Level 3

If $a+b+c=0$ , $a^2+b^2+c^2=4$ Then find $a^4+b^4+c^4$ .

4 16 2 8

1 solution

Otto Bretscher
Mar 3, 2016

Since $p_1=0$ , Girard's equations give $p_4=\frac{p_2^2}{2}=\boxed{8}$ , where $p_k=a^k+b^k+c^k$

Didn't know we could it this way~~+1:)

Shishir Shahi - 3 years, 10 months ago