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, \(\frac{1-\tan^2(45^\circ-A)}{1+\tan^2(45^\circ-A)} = \sin 2A\) 🥰
