The sum of the fourth powers of the roots of the equation $x^3+x+1=0$ is
The sum of the fourth powers of the roots of the equation $x^3+x+1=0$ is
- $-2$
- $-1$
- $1$
- $2$
Solution
Given equation is $x^3+x+1=0$
On comparing with $x^3+p_1 x^2+p_2 x+p_3=0$, we get
Now,
$
p_1=0, p_2=1, p_3=1
$
$
\begin{aligned}
& S_2+0 \cdot S_1+2=0 \Rightarrow S_2=-2 \\
& S_3+0 \cdot S_2+1 \cdot S_1+(2)=0 \Rightarrow S_3=-2 \\
& S_4+0 \cdot S_3+1 \cdot S_2+1 \cdot S_1=0 \\
& \Rightarrow \quad S_4+0+1(-2)+1(0)=0 \\
& S_4=2
\end{aligned}
$
$
S_1=0, S_0=2
$
Asked in: AP EAMCET 2008
Practice more Quadratic Equation questions on Aicharya