Question-87369

Question Number 87369 by ajfour last updated on 04/Apr/20

Commented by ajfour last updated on 04/Apr/20

I t h i n k, \frac{R}{r} = 3 + 2 \sqrt{2} o n l y, S i r .

Commented by ajfour last updated on 04/Apr/20

F i n d R / r .

Commented by Prithwish Sen 1 last updated on 04/Apr/20

3 \pm 2 \sqrt{2}

Commented by Prithwish Sen 1 last updated on 04/Apr/20

yes . thank you .

Answered by mr W last updated on 04/Apr/20

Commented by mr W last updated on 04/Apr/20

β + γ = \frac{π}{2}

\cos β = \frac{R - r}{R + r}

\cos γ = \frac{R - r}{R + r} = \cos β

\Rightarrow β = γ = \frac{π}{4}

\frac{R - r}{R + r} = \frac{\sqrt{2}}{2}

\frac{\frac{R}{r} - 1}{\frac{R}{r} + 1} = \frac{\sqrt{2}}{2}

\Rightarrow \frac{R}{r} = \frac{2 + \sqrt{2}}{2 - \sqrt{2}} = 3 + 2 \sqrt{2}

Commented by Prithwish Sen 1 last updated on 04/Apr/20

wow! excellent sir .

Commented by ajfour last updated on 04/Apr/20

T h a n k y o u b o t h m r W S i r & S e n S i r .

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