Explanation:

Another Explanation (5): ```html

tan θ = 1/7 হলে, cos 2θ এর মান নির্ণয়:

আমরা জানি, \(cos 2θ = \frac{1 - tan^2 θ}{1 + tan^2 θ}\) 🤓 এখানে, \(tan θ = \frac{1}{7}\) 🤔 দেওয়া আছে। সুতরাং, \(tan^2 θ = (\frac{1}{7})^2 = \frac{1}{49}\) 🤩 এখন, \(cos 2θ\) এর মান বের করি: \(cos 2θ = \frac{1 - \frac{1}{49}}{1 + \frac{1}{49}}\) 😎 \(cos 2θ = \frac{\frac{49 - 1}{49}}{\frac{49 + 1}{49}}\) 🥳 \(cos 2θ = \frac{\frac{48}{49}}{\frac{50}{49}}\) 🤫 \(cos 2θ = \frac{48}{49} \times \frac{49}{50}\) 😲 \(cos 2θ = \frac{48}{50}\) 😌 \(cos 2θ = \frac{24}{25}\) 🥰 অতএব, \(cos 2θ\) এর মান \(\frac{24}{25}\)। 🎉 ```