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If x+y+z=0,x2y2+y2z2+z2x2x4+y4+z4=?x+y+z=0, \quad \frac{x^{2} y^{2}+y^{2} z^{2}+z^{2} x^{2}}{x^{4}+y^{4}+z^{4}}=?

a

0

b

1

c

12\frac{1}{2}

d

32\frac{3}{2}

Answer : Option C
Explanation :
x + y + z = 0 (x+y+z)2=0\Rightarrow(x+y+z)^{2}=0 x2+y2+z2+2(xy+yz+zx)=0\Rightarrow x^{2}+y^{2}+z^{2}+2(x y+y z+z x)=0 x2+y2+z2=2(xy+yz+zx)\Rightarrow x^{2}+y^{2}+z^{2}=-2(x y+y z+z x) दोनों पक्षों का वर्ग करने पर, (x2< sup>< sup> + y2 < sup>< sup>+ z2< sup>< sup>)2< sup>< sup> = 4 (xy + yz + zx)2< sup>< sup> (x2+y2+z2)2=4(xy+yz+zx)2\left(x^{2}+y^{2}+z^{2}\right)^{2}=4(x y+y z+z x)^{2} =4(x2y2+y2z2+z2x2+2xy2z+2xyz2+2x2yz)=4\left(x^{2} y^{2}+y^{2} z^{2}+z^{2} x^{2}+2 x y^{2} z+2 x y z^{2}+2 x^{2} y z\right) x4+y4+z4=2(x2y2+y2z2+z2x2)+2xyz(x+y+z)\begin{aligned} \Rightarrow & x^{4}+y^{4}+z^{4}=2\left(x^{2} y^{2}+y^{2} z^{2}+z^{2} x^{2}\right)+2 x y z(x+y\\ &+z) \end{aligned} x4+y4+z4=2(x2y2+y2z2+z2x2)[x+y+z=0]\begin{aligned} \Rightarrow & x^{4}+y^{4}+z^{4}=2\left(x^{2} y^{2}+y^{2} z^{2}+z^{2} x^{2}\right) \\ &[\because x+y+z=0] \end{aligned} x2y2+y2z2+z2x2x4+y4+z4=12\Rightarrow \frac{x^{2} y^{2}+y^{2} z^{2}+z^{2} x^{2}}{x^{4}+y^{4}+z^{4}}=\frac{1}{2}

विकल्प:

दिया गया है : x + y + z = 0

मान लीजिए x = 0

y = 1

z = –1

प्रश्न के अनुसार

xyy2+y2z2+z2x2x4+y4+z4=0+1+00+1+1=12\Rightarrow \frac{x^{y} y^{2}+y^{2} z^{2}+z^{2} x^{2}}{x^{4}+y^{4}+z^{4}}=\frac{0+1+0}{0+1+1}=\frac{1}{2}

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