Question Number 146622 by mathdanisur last updated on 14/Jul/21
$$\frac{\mathrm{1}}{\:\sqrt[{\mathrm{8}}]{\mathrm{6}}\:+\:\mathrm{1}}\:\centerdot\:\frac{\mathrm{1}}{\:\sqrt[{\mathrm{4}}]{\mathrm{6}}\:+\:\mathrm{1}}\:\centerdot\:\frac{\mathrm{1}}{\:\sqrt{\mathrm{6}}\:+\:\mathrm{1}}\:+\:\mathrm{1}\:=\:? \\ $$
Commented by hknkrc46 last updated on 14/Jul/21
$$\bigstar\:\frac{\mathrm{1}}{\left(\sqrt[{\mathrm{8}}]{\mathrm{6}}\:+\:\mathrm{1}\right)\left(\sqrt[{\mathrm{4}}]{\mathrm{6}}\:+\:\mathrm{1}\right)\left(\sqrt{\mathrm{6}}\:+\:\mathrm{1}\right)}\:+\:\mathrm{1} \\ $$$$=\:\frac{\sqrt[{\mathrm{8}}]{\mathrm{6}}\:−\:\mathrm{1}}{\underset{\sqrt[{\mathrm{4}}]{\mathrm{6}}\:−\:\mathrm{1}} {\underbrace{\left(\sqrt[{\mathrm{8}}]{\mathrm{6}}\:−\:\mathrm{1}\right)\left(\sqrt[{\mathrm{8}}]{\mathrm{6}}\:+\:\mathrm{1}\right)}}\left(\sqrt[{\mathrm{4}}]{\mathrm{6}}\:+\:\mathrm{1}\right)\left(\sqrt{\mathrm{6}}\:+\:\mathrm{1}\right)}\:+\:\mathrm{1} \\ $$$$=\:\frac{\sqrt[{\mathrm{8}}]{\mathrm{6}}\:−\:\mathrm{1}}{\underset{\sqrt{\mathrm{6}}\:−\:\mathrm{1}} {\underbrace{\left(\sqrt[{\mathrm{4}}]{\mathrm{6}}\:−\:\mathrm{1}\right)\left(\sqrt[{\mathrm{4}}]{\mathrm{6}}\:+\:\mathrm{1}\right)}}\left(\sqrt{\mathrm{6}}\:+\:\mathrm{1}\right)}\:+\:\mathrm{1} \\ $$$$=\:\frac{\sqrt[{\mathrm{8}}]{\mathrm{6}}\:−\:\mathrm{1}}{\left(\sqrt{\mathrm{6}}\:−\:\mathrm{1}\right)\left(\sqrt{\mathrm{6}}\:+\:\mathrm{1}\right)}\:+\:\mathrm{1}\: \\ $$$$=\:\frac{\sqrt[{\mathrm{8}}]{\mathrm{6}}\:−\:\mathrm{1}}{\mathrm{6}\:−\:\mathrm{1}}\:+\:\mathrm{1}\:=\:\frac{\sqrt[{\mathrm{8}}]{\mathrm{6}}\:−\:\mathrm{1}}{\mathrm{5}}\:+\:\mathrm{1}\: \\ $$$$=\:\frac{\sqrt[{\mathrm{8}}]{\mathrm{6}}\:+\:\mathrm{4}}{\mathrm{5}} \\ $$
Answered by som(math1967) last updated on 14/Jul/21
$$\frac{\sqrt[{\mathrm{8}}]{\mathrm{6}}−\mathrm{1}}{\left(^{\mathrm{8}} \sqrt{\mathrm{6}}−\mathrm{1}\right)\left(^{\mathrm{8}} \sqrt{\mathrm{6}}+\mathrm{1}\right)\left(^{\mathrm{4}} \sqrt{\mathrm{6}}+\mathrm{1}\right)\left(\sqrt{\mathrm{6}}+\mathrm{1}\right)}\:+\mathrm{1} \\ $$$$=\frac{\sqrt[{\mathrm{8}}]{\mathrm{6}}−\mathrm{1}}{\left(^{\mathrm{4}} \sqrt{\mathrm{6}}−\mathrm{1}\right)\left(^{\mathrm{4}} \sqrt{\mathrm{6}}+\mathrm{1}\right)\left(\sqrt{\mathrm{6}}+\mathrm{1}\right)}\:+\mathrm{1} \\ $$$$=\frac{\sqrt[{\mathrm{8}}]{\mathrm{6}}−\mathrm{1}}{\:\left(\sqrt{\mathrm{6}}−\mathrm{1}\right)\left(\sqrt{\mathrm{6}}+\mathrm{1}\right)}\:+\mathrm{1} \\ $$$$=\frac{\sqrt[{\mathrm{8}}]{\mathrm{6}}−\mathrm{1}}{\mathrm{6}−\mathrm{1}}\:+\mathrm{1}=\frac{\sqrt[{\mathrm{8}}]{\mathrm{6}}}{\mathrm{5}}\:+\frac{\mathrm{4}}{\mathrm{5}} \\ $$
Commented by mathdanisur last updated on 14/Jul/21
$${thanks}\:{Ser},\:{but}\:{answer}:\:\:\sqrt[{\mathrm{8}}]{\mathrm{6}} \\ $$
Commented by som(math1967) last updated on 14/Jul/21
$${where}\:{is}\:\boldsymbol{{wrong}}\:? \\ $$
Commented by mathdanisur last updated on 14/Jul/21
$${Ser},\:{maybe}\:{the}\:{answer}\:{is}\:{wrong} \\ $$
Commented by som(math1967) last updated on 14/Jul/21
$${let}\:\frac{\mathrm{1}}{\left(^{\mathrm{8}} \sqrt{\mathrm{6}}+\mathrm{1}\right)\left(^{\mathrm{4}} \sqrt{\mathrm{6}}+\mathrm{1}\right)\left(\sqrt{\mathrm{6}}+\mathrm{1}\right)}\:+\mathrm{1}=^{\mathrm{8}} \sqrt{\mathrm{6}} \\ $$$$\frac{\mathrm{1}}{\left(^{\mathrm{8}} \sqrt{\mathrm{6}}+\mathrm{1}\right)\left(^{\mathrm{4}} \sqrt{\mathrm{6}}+\mathrm{1}\right)\left(\sqrt{\mathrm{6}}+\mathrm{1}\right)}=^{\mathrm{8}} \sqrt{\mathrm{6}}−\mathrm{1} \\ $$$$\frac{\mathrm{1}}{\left(^{\mathrm{8}} \sqrt{\mathrm{6}}+\mathrm{1}\right)\left(^{\mathrm{4}} \sqrt{\mathrm{6}}+\mathrm{1}\right)\left(\sqrt{\mathrm{6}}+\mathrm{1}\right)\left(^{\mathrm{8}} \sqrt{\mathrm{6}}−\mathrm{1}\right)}=\mathrm{1} \\ $$$$\frac{\mathrm{1}}{\mathrm{6}−\mathrm{1}}=\mathrm{1} \\ $$$$\therefore\frac{\mathrm{1}}{\mathrm{5}}=\mathrm{1}\:\:?????? \\ $$$${so}\:{I}\:{think}\:{ans}\:{is}\:{wrong} \\ $$
Commented by mathdanisur last updated on 14/Jul/21
$${answer}\:{wrong}\:{Ser},\:{thank}\:{you} \\ $$