Question
Form the quadratic equation from the roots given below : 3 and -10
✓
Answer
Let $\alpha=3$ and $\beta=-10$
$\therefore \alpha+\beta=3-10=-7$ and $\alpha \beta=3 \times-10=-30$
$\therefore$ and quadratic equation is, $x^2-(\alpha+\beta) x+\alpha \beta=0$
$\begin{array}{l}
\therefore x ^2-(-7) x +(-30)=0 \\
\therefore x ^2+7 x -30=0
\end{array}$
$\therefore \alpha+\beta=3-10=-7$ and $\alpha \beta=3 \times-10=-30$
$\therefore$ and quadratic equation is, $x^2-(\alpha+\beta) x+\alpha \beta=0$
$\begin{array}{l}
\therefore x ^2-(-7) x +(-30)=0 \\
\therefore x ^2+7 x -30=0
\end{array}$
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