(cos10°-sin10°)/(cos10°+sin10°)=? 

Explanation:

Another Explanation (5): \( \frac{\cos 10^\circ - \sin 10^\circ}{\cos 10^\circ + \sin 10^\circ} \) অংশ এবং হরকে \( \cos 10^\circ \) দিয়ে ভাগ করে পাই, \( = \frac{\frac{\cos 10^\circ}{\cos 10^\circ} - \frac{\sin 10^\circ}{\cos 10^\circ}}{\frac{\cos 10^\circ}{\cos 10^\circ} + \frac{\sin 10^\circ}{\cos 10^\circ}} \) \( = \frac{1 - \tan 10^\circ}{1 + \tan 10^\circ} \) আমরা জানি, \( \tan 45^\circ = 1 \). সুতরাং, \( = \frac{\tan 45^\circ - \tan 10^\circ}{1 + \tan 45^\circ \cdot \tan 10^\circ} \) \( \tan (A - B) = \frac{\tan A - \tan B}{1 + \tan A \tan B} \) এই সূত্র ব্যবহার করে পাই, \( = \tan (45^\circ - 10^\circ) \) \( = \tan 35^\circ \) সুতরাং, \( \frac{\cos 10^\circ - \sin 10^\circ}{\cos 10^\circ + \sin 10^\circ} = \tan 35^\circ \) 🥳