Question Number 221411 by ajfour last updated on 03/Jun/25

Answered by mr W last updated on 04/Jun/25

$${r}=\frac{\theta}{\mathrm{2}\:\mathrm{sin}\:\theta}=\frac{\pi}{\mathrm{6}} \\ $$
Commented by mr W last updated on 07/Jun/25

$${i}\:{think}\:{you}\:{can}\:{know}\:{by}\:{yourself} \\ $$$${that}\:{it}\:{is}\:{not}\:{a}\:{clear}\:{and}\:{solvable} \\ $$$${question}\:{but}\:{a}\:{non}−{sense}. \\ $$
Commented by mr W last updated on 04/Jun/25

Commented by mr W last updated on 04/Jun/25

$$\frac{\theta}{\mathrm{tan}\:\theta}=\mathrm{2}×\mathrm{1}\:\mathrm{sin}\:\frac{\mathrm{1}}{\mathrm{2}}\left(\frac{\pi}{\mathrm{2}}−\theta\right) \\ $$$$\frac{\theta}{\mathrm{tan}\:\theta}=\sqrt{\mathrm{2}}\left(\mathrm{cos}\:\frac{\theta}{\mathrm{2}}−\mathrm{sin}\:\frac{\theta}{\mathrm{2}}\right) \\ $$$$\frac{\theta^{\mathrm{2}} }{\mathrm{tan}^{\mathrm{2}} \:\theta}=\mathrm{2}\left(\mathrm{1}−\mathrm{sin}\:\theta\right) \\ $$$$\theta^{\mathrm{2}} \left(\mathrm{1}+\mathrm{sin}\:\theta\right)=\mathrm{2}\:\mathrm{sin}^{\mathrm{2}} \:\theta \\ $$$$\Rightarrow\theta\approx\mathrm{0}.\mathrm{731365}\:\left(\mathrm{41}.\mathrm{9}°\right) \\ $$
Commented by ajfour last updated on 04/Jun/25

$${yes}!\:{Thank}\:{you}.\:{If}\:{blue}\:{circle}\:{crosses}\:{also} \\ $$$${point}\:\left(\mathrm{0},\mathrm{1}\right)\:{find}\:\theta. \\ $$
Commented by mr W last updated on 05/Jun/25

$${ORPQ}\:{is}\:{cyclic}. \\ $$$${QR}\:{is}\:{diameter}\:{of}\:{the}\:{smaller}\:{circle}. \\ $$$$\alpha=\frac{\pi}{\mathrm{2}}−\theta \\ $$$${RP}=\frac{{QP}}{\mathrm{tan}\:\theta}=\frac{\theta}{\mathrm{tan}\:\theta} \\ $$$${RP}=\mathrm{2}×{OP}\:\mathrm{sin}\:\frac{\alpha}{\mathrm{2}}=\mathrm{2}×\mathrm{1}\:\mathrm{sin}\:\frac{\mathrm{1}}{\mathrm{2}}\left(\frac{\pi}{\mathrm{2}}−\theta\right) \\ $$$$\:\:\:\:\:\:\:=\mathrm{2}\:\mathrm{sin}\:\left(\frac{\pi}{\mathrm{4}}−\frac{\theta}{\mathrm{2}}\right)=\sqrt{\mathrm{2}}\:\left(\mathrm{cos}\:\frac{\theta}{\mathrm{2}}−\mathrm{sin}\:\frac{\theta}{\mathrm{2}}\right) \\ $$$$\Rightarrow\frac{\theta}{\mathrm{tan}\:\theta}=\sqrt{\mathrm{2}}\:\left(\mathrm{cos}\:\frac{\theta}{\mathrm{2}}−\mathrm{sin}\:\frac{\theta}{\mathrm{2}}\right) \\ $$$$\Rightarrow\frac{\theta^{\mathrm{2}} \:\mathrm{cos}^{\mathrm{2}} \:\theta}{\mathrm{sin}^{\mathrm{2}} \:\theta}=\mathrm{2}\left(\mathrm{cos}\:\frac{\theta}{\mathrm{2}}−\mathrm{sin}\:\frac{\theta}{\mathrm{2}}\right)^{\mathrm{2}} \\ $$$$\Rightarrow\frac{\theta^{\mathrm{2}} \left(\mathrm{1}−\mathrm{sin}^{\mathrm{2}} \:\theta\right)}{\mathrm{sin}^{\mathrm{2}} \:\theta}=\mathrm{2}\left(\mathrm{1}−\mathrm{sin}\:\theta\right) \\ $$$$\Rightarrow\frac{\theta^{\mathrm{2}} \left(\mathrm{1}+\mathrm{sin}\:\theta\right)}{\mathrm{sin}^{\mathrm{2}} \:\theta}=\mathrm{2} \\ $$$$\Rightarrow\theta^{\mathrm{2}} \left(\mathrm{1}+\mathrm{sin}\:\theta\right)=\mathrm{2}\:\mathrm{sin}^{\mathrm{2}} \:\theta \\ $$
Commented by mr W last updated on 05/Jun/25

Commented by mr W last updated on 04/Jun/25

$${with}\:\theta\approx\mathrm{0}.\mathrm{731365}\:\left(\mathrm{41}.\mathrm{9}°\right)\:{we}\:{get}\:{this}: \\ $$
Commented by mr W last updated on 04/Jun/25

Commented by ajfour last updated on 04/Jun/25

$${yeah}\:{must}\:{be}\:{true}\:{then}\:{but}\:{i}\:{could}\:{not} \\ $$$${follow}\:{your}\:{solution}\:{sir}. \\ $$
Commented by ajfour last updated on 05/Jun/25

$${thanks}\:{sir}.\:{Got}\:{it}.\: \\ $$
Commented by Tawa11 last updated on 05/Jun/25

$$\mathrm{Weldone}\:\mathrm{sirs}. \\ $$$$\mathrm{Please}\:\mathrm{help}\:\mathrm{when}\:\mathrm{chanced}\:\mathrm{sirs}.\:\:\mathrm{Q221444} \\ $$
Commented by mr W last updated on 05/Jun/25

$${do}\:{you}\:{understand}\:{that}\:{question}? \\ $$$${i}\:{don}'{t}.\:{so}\:{i}\:{wont}\:{waste}\:{my}\:{timefor} \\ $$$${it}. \\ $$
Commented by Tawa11 last updated on 05/Jun/25

$$\mathrm{Sir},\:\mathrm{I}\:\mathrm{don}'\mathrm{t}\:\mathrm{understand}\:\mathrm{too}. \\ $$$$\mathrm{Please}\:\mathrm{based}\:\mathrm{on}\:\mathrm{your}\:\mathrm{experience}, \\ $$$$\mathrm{is}\:\mathrm{the}\:\mathrm{diagram}\:\mathrm{drawn}\:\mathrm{correctly}. \\ $$$$\mathrm{What}\:\mathrm{do}\:\mathrm{you}\:\mathrm{think}\:\mathrm{is}\:\mathrm{not}\:\mathrm{set}\:\mathrm{well}\:\mathrm{in} \\ $$$$\mathrm{the}\:\mathrm{question}. \\ $$$$\mathrm{What}\:\mathrm{correction}\:\mathrm{do}\:\mathrm{you}\:\mathrm{think}\:\mathrm{can}\:\mathrm{be}\:\mathrm{mbade}? \\ $$
Commented by mr W last updated on 05/Jun/25

$${that}\:{question}\:{is}\:{a}\:{non}−{sense}\:{to}\:{me}. \\ $$$${i}\:{don}'{t}\:{understand}\:{it}\:{and}\:{wont}\:{waste} \\ $$$${time}\:{for}\:{it}.\: \\ $$
Commented by Tawa11 last updated on 05/Jun/25

$$\mathrm{Thanks}\:\mathrm{sir}. \\ $$
Commented by Tawa11 last updated on 06/Jun/25

$$\mathrm{Sir},\:\mathrm{please}\:\mathrm{check}\:\mathrm{the}\:\mathrm{new}\:\mathrm{modification} \\ $$$$\mathrm{after}\:\mathrm{I}\:\mathrm{complained}.\:\mathrm{If}\:\mathrm{it}\:\mathrm{is}\:\mathrm{solvable}. \\ $$$$\mathrm{Please}\:\mathrm{help}\:\mathrm{sir}.\:\:\mathrm{Q221444} \\ $$
Commented by Tawa11 last updated on 06/Jun/25

$$\mathrm{I}\:\mathrm{opened}\:\mathrm{new}\:\mathrm{tab}.\:\mathrm{Q221495} \\ $$
Commented by Tawa11 last updated on 07/Jun/25

$$\mathrm{I}\:\mathrm{am}\:\mathrm{asking}\:\mathrm{incase}\:\mathrm{they}\:\mathrm{have}\:\mathrm{error}\:\mathrm{again} \\ $$$$\mathrm{in}\:\mathrm{the}\:\mathrm{question}. \\ $$
Commented by Tawa11 last updated on 07/Jun/25

$$\mathrm{Sir},\:\mathrm{your}\:\mathrm{experience}\:\mathrm{is}\:\mathrm{more}\:\mathrm{than}\:\mathrm{my}\:\mathrm{own}. \\ $$$$\mathrm{That}\:\mathrm{is}\:\mathrm{why}\:\mathrm{I}\:\mathrm{asked}\:\mathrm{you}\:\mathrm{sir}. \\ $$$$\mathrm{My}\:\mathrm{geometry}\:\mathrm{skill}\:\mathrm{is}\:\:\mathrm{1}/\mathrm{1000}\:\mathrm{of}\:\mathrm{your}\:\mathrm{own}\:\mathrm{sir}. \\ $$$$\mathrm{Hahahahahahaha}!!! \\ $$