Question Number 146989 by mathdanisur last updated on 16/Jul/21
$${Simplify}: \\ $$$$\frac{{x}^{\frac{\mathrm{1}}{\mathrm{2}}} \:+\:{y}^{\frac{\mathrm{1}}{\mathrm{2}}} }{{x}^{\frac{\mathrm{1}}{\mathrm{6}}} \:+\:{y}^{\frac{\mathrm{1}}{\mathrm{6}}} }\:\:-\:\:\frac{{x}^{\frac{\mathrm{1}}{\mathrm{2}}} \:-\:{y}^{\frac{\mathrm{1}}{\mathrm{2}}} }{{x}^{\frac{\mathrm{1}}{\mathrm{6}}} \:-\:{y}^{\frac{\mathrm{1}}{\mathrm{6}}} }\:=\:? \\ $$
Commented by 7770 last updated on 17/Jul/21
$$\boldsymbol{\mathrm{let}}\:\boldsymbol{\mathrm{x}}^{\mathrm{0}.\mathrm{5}} =\boldsymbol{\mathrm{a}}\:\:\:\:\boldsymbol{\mathrm{y}}^{\mathrm{0}.\mathrm{5}} =\boldsymbol{\mathrm{b}}\:\:\:\:\boldsymbol{\mathrm{x}}^{\frac{\mathrm{1}}{\mathrm{6}}} =\boldsymbol{\mathrm{m}}\:\:\boldsymbol{\mathrm{y}}^{\frac{\mathrm{1}}{\mathrm{6}}} =\boldsymbol{\mathrm{n}} \\ $$$$\frac{\boldsymbol{\mathrm{a}}+\boldsymbol{\mathrm{b}}}{\boldsymbol{\mathrm{m}}+\boldsymbol{\mathrm{n}}}−\frac{\boldsymbol{\mathrm{a}}−\boldsymbol{\mathrm{b}}}{\boldsymbol{\mathrm{m}}−\boldsymbol{\mathrm{n}}}\Rightarrow\frac{\boldsymbol{\mathrm{a}}^{\mathrm{2}} −\boldsymbol{\mathrm{b}}^{\mathrm{2}} }{\boldsymbol{\mathrm{m}}^{\mathrm{2}} −\boldsymbol{\mathrm{n}}^{\mathrm{2}} } \\ $$$$\frac{\boldsymbol{\mathrm{x}}−\boldsymbol{\mathrm{y}}}{\:\sqrt[{\mathrm{3}}]{\boldsymbol{\mathrm{x}}}−\sqrt[{\mathrm{3}}]{\boldsymbol{\mathrm{y}}}} \\ $$
Commented by Rasheed.Sindhi last updated on 17/Jul/21
$$\frac{\boldsymbol{\mathrm{a}}+\boldsymbol{\mathrm{b}}}{\boldsymbol{\mathrm{m}}+\boldsymbol{\mathrm{n}}}−\frac{\boldsymbol{\mathrm{a}}−\boldsymbol{\mathrm{b}}}{\boldsymbol{\mathrm{m}}−\boldsymbol{\mathrm{n}}}\Rightarrow\frac{\boldsymbol{\mathrm{a}}^{\mathrm{2}} −\boldsymbol{\mathrm{b}}^{\mathrm{2}} }{\boldsymbol{\mathrm{m}}^{\mathrm{2}} −\boldsymbol{\mathrm{n}}^{\mathrm{2}} }\:??? \\ $$$$\frac{\boldsymbol{\mathrm{a}}+\boldsymbol{\mathrm{b}}}{\boldsymbol{\mathrm{m}}+\boldsymbol{\mathrm{n}}}×\frac{\boldsymbol{\mathrm{a}}−\boldsymbol{\mathrm{b}}}{\boldsymbol{\mathrm{m}}−\boldsymbol{\mathrm{n}}}=\frac{\boldsymbol{\mathrm{a}}^{\mathrm{2}} −\boldsymbol{\mathrm{b}}^{\mathrm{2}} }{\boldsymbol{\mathrm{m}}^{\mathrm{2}} −\boldsymbol{\mathrm{n}}^{\mathrm{2}} } \\ $$
Answered by bobhans last updated on 17/Jul/21
$$\begin{cases}{\mathrm{x}^{\mathrm{1}/\mathrm{6}} =\mathrm{u}}\\{\mathrm{y}^{\mathrm{1}/\mathrm{6}} =\mathrm{v}}\end{cases} \\ $$$$\Rightarrow\:\frac{\mathrm{u}^{\mathrm{3}} +\mathrm{v}^{\mathrm{3}} }{\mathrm{u}+\mathrm{v}}\:−\:\frac{\mathrm{u}^{\mathrm{3}} −\mathrm{v}^{\mathrm{3}} }{\mathrm{u}−\mathrm{v}}=\mathrm{u}^{\mathrm{2}} −\mathrm{uv}+\mathrm{v}^{\mathrm{2}} −\left(\mathrm{u}^{\mathrm{2}} +\mathrm{uv}+\mathrm{v}^{\mathrm{2}} \right) \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:=\:−\mathrm{2uv}\:=−\mathrm{2}\left(\mathrm{xy}\right)^{\mathrm{1}/\mathrm{6}} \\ $$
Commented by mathdanisur last updated on 17/Jul/21
$${thank}\:{you}\:{Ser} \\ $$