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Question-170914




Question Number 170914 by mathlove last updated on 03/Jun/22
Commented by infinityaction last updated on 03/Jun/22
x =  (1/(^3 (√2) −1))       g.p. sum  1+(1/x) =^3 (√(2 ))  (1+(1/x))^3  = 2
$${x}\:=\:\:\frac{\mathrm{1}}{\:^{\mathrm{3}} \sqrt{\mathrm{2}}\:−\mathrm{1}}\:\:\:\:\:\:\:{g}.{p}.\:{sum} \\ $$$$\mathrm{1}+\frac{\mathrm{1}}{{x}}\:=\:^{\mathrm{3}} \sqrt{\mathrm{2}\:} \\ $$$$\left(\mathrm{1}+\frac{\mathrm{1}}{{x}}\right)^{\mathrm{3}} \:=\:\mathrm{2} \\ $$
Commented by cortano1 last updated on 04/Jun/22
 (1+(1/( (4)^(1/3) +(2)^(1/3) +1)) .(((2)^(1/3) −1)/( (2)^(1/3) −1)))^3   =(1+(((2)^(1/3) −1)/(((2)^(1/3) )^3 −1)))^3   =(1+(((2)^(1/3) −1)/(2−1)))^3 = ((2)^(1/3)  )^3 =2
$$\:\left(\mathrm{1}+\frac{\mathrm{1}}{\:\sqrt[{\mathrm{3}}]{\mathrm{4}}+\sqrt[{\mathrm{3}}]{\mathrm{2}}+\mathrm{1}}\:.\frac{\sqrt[{\mathrm{3}}]{\mathrm{2}}−\mathrm{1}}{\:\sqrt[{\mathrm{3}}]{\mathrm{2}}−\mathrm{1}}\right)^{\mathrm{3}} \\ $$$$=\left(\mathrm{1}+\frac{\sqrt[{\mathrm{3}}]{\mathrm{2}}−\mathrm{1}}{\left(\sqrt[{\mathrm{3}}]{\mathrm{2}}\right)^{\mathrm{3}} −\mathrm{1}}\right)^{\mathrm{3}} \\ $$$$=\left(\mathrm{1}+\frac{\sqrt[{\mathrm{3}}]{\mathrm{2}}−\mathrm{1}}{\mathrm{2}−\mathrm{1}}\right)^{\mathrm{3}} =\:\left(\sqrt[{\mathrm{3}}]{\mathrm{2}}\:\right)^{\mathrm{3}} =\mathrm{2} \\ $$
Commented by mathlove last updated on 04/Jun/22
tanks for all
$${tanks}\:{for}\:{all} \\ $$
Answered by mahdipoor last updated on 03/Jun/22
(^3 (√4)+^3 (√2)+1)(^3 (√2)−1)=1⇒1/x=^3 (√2)−1  (1+1/x)^3 =(1+^3 (√2)−1)^3 =2
$$\left(^{\mathrm{3}} \sqrt{\mathrm{4}}+^{\mathrm{3}} \sqrt{\mathrm{2}}+\mathrm{1}\right)\left(^{\mathrm{3}} \sqrt{\mathrm{2}}−\mathrm{1}\right)=\mathrm{1}\Rightarrow\mathrm{1}/{x}=^{\mathrm{3}} \sqrt{\mathrm{2}}−\mathrm{1} \\ $$$$\left(\mathrm{1}+\mathrm{1}/{x}\right)^{\mathrm{3}} =\left(\mathrm{1}+^{\mathrm{3}} \sqrt{\mathrm{2}}−\mathrm{1}\right)^{\mathrm{3}} =\mathrm{2} \\ $$

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