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4-1.Complex numbers
medium
समीकरण को हल कीजिए
$27 x^{2}-10 x+1=0$
A
$\frac{5}{27} \pm \frac{\sqrt{2}}{27} i$
B
$\frac{5}{27} \pm \frac{\sqrt{2}}{27} i$
C
$\frac{5}{27} \pm \frac{\sqrt{2}}{27} i$
D
$\frac{5}{27} \pm \frac{\sqrt{2}}{27} i$
Solution
The given quadratic equation is $27 x^{2}-10 x+1=0$
On comparing this equation with $a x^{2}+b x+c=0,$ we obtain $a=27, b=-10$ and $c=1$
Therefore, the discriminant of the given equation is
$D=b^{2}-4 a c=(-10)^{2}-4 \times 27 \times 1=100-108=-8$
Therefore, the required solutions are
$\frac{-b \pm \sqrt{D}}{2 a}=\frac{-(-10) \pm \sqrt{-8}}{2 \times 27}=\frac{10 \pm 2 \sqrt{2} i}{54} \quad[\sqrt{-1}=i]$
$=\frac{5 \pm \sqrt{2} i}{27}=\frac{5}{27} \pm \frac{\sqrt{2}}{27} i$
Standard 11
Mathematics