## Online Course Discussion Forum

### Question about online summer camp 2021 Algebra blue group problem P6

Question about online summer camp 2021 Algebra blue group problem P6

Let a, b, c, d be the roots of x^4 − 5x^2 + 3x + 1. Evaluate a^4 + b^4 + c^4 + d^4 .

I am having trouble doing this problem. While I could find a^2+b^2+c^2+d^2=19 using Vieta's formula, I am stuck and do not know how to get the answer the question is asking for. Can someone help?

Re: Question about online summer camp 2021 Algebra blue group problem P6

This is one of those problems where we can use the given equations to reduce some exponents.

Since you know that $a$ is a root of $x^4 -5x^2+3x+1$, then $a^4 - 5a^2 + 3a + 1 = 0$, that is, $a^4 = 5a^2 -3a -1$.