(1-tan^2(45°-A))/(1+tan^2(45°-A))=? 

Explanation:

Another Explanation (5): প্রদত্ত রাশি: \(\frac{1-\tan^2(45^\circ-A)}{1+\tan^2(45^\circ-A)}\) আমরা জানি, \(\cos 2\theta = \frac{1-\tan^2\theta}{1+\tan^2\theta}\) 🤓 সুতরাং, \(\frac{1-\tan^2(45^\circ-A)}{1+\tan^2(45^\circ-A)} = \cos[2(45^\circ-A)]\) 🤩 \(= \cos(90^\circ - 2A)\) 🥳 আমরা আরও জানি, \(\cos(90^\circ - \theta) = \sin \theta\) 😎 সুতরাং, \(\cos(90^\circ - 2A) = \sin 2A\) 😇 অতএব, \(\frac{1-\tan^2(45^\circ-A)}{1+\tan^2(45^\circ-A)} = \sin 2A\) 🥰