Solve x^{2}+x+1=0

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4-1.Complex numbers

easy

Solve $x^{2}+x+1=0$

A

$\frac{-1 \pm \sqrt{3} i}{2}$

B

$\frac{-1 \pm \sqrt{3} i}{2}$

C

$\frac{-1 \pm \sqrt{3} i}{2}$

D

$\frac{-1 \pm \sqrt{3} i}{2}$

Solution

Here, $b^{2}-4 a c=1^{2}-4 \times 1 \times 1=1-4=-3$

Therefore, the solutions are given by $x=\frac{-1 \pm \sqrt{-3}}{2 \times 1}=\frac{-1 \pm \sqrt{3} i}{2}$

Standard 11

Mathematics

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