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अगर x=323+2x=\frac{\sqrt{3}-\sqrt{2}}{\sqrt{3}+\sqrt{2}} और y=3+232y=\frac{\sqrt{3}+\sqrt{2 }}{\sqrt{3}-\sqrt{2}}, तो x3+y3x^{3}+y^{3} का मूल्य है:

a

950

b

730

c

650

d

970

Answer : Option D
Explanation :

k=323+2=(32)(32)(3+2)(32)k=\frac{\sqrt{3}-\sqrt{2}}{\sqrt{3}+\sqrt{2}}=\frac{(\sqrt{3}-\sqrt{2})(\sqrt{3}-\sqrt{2})}{(\sqrt{3}+\sqrt{2})(\sqrt{3}-\sqrt{2})}

=(32)232=3+2232=\frac{(\sqrt{3}-\sqrt{2})^{2}}{3-2}=3+2-2 \sqrt{3} \cdot \sqrt{2}

x+y=526+5+26=10\therefore x+y=5-2 \sqrt{6}+5+2 \sqrt{6}=10

xy=(526)(5+26)=2524=1x y=(5-2 \sqrt{6})(5+2 \sqrt{6})=25-24=1

∴ x³ + y³ = (x + y)³ – 3xy (x + y) = (10)³ – 3(10)

= 1000 – 30 = 970

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