উত্তর সিলেক্ট করলে সঠিক ও ভুল দেখাবে।
ব্যাখ্যা ও সঠিক সমাধান
উত্তর:
√2+√3
2cos(π/12) = 2√(cos²(π/12)) = 2√((1+cos(π/6))/2) = 2√( (1+√3/2)/2 ) = 2√( (2+√3)/4 ) = √(2+√3) = √( (4+2√3)/2 ) = (√3+1)/√2 = √6/2 + √2/2 (Wait, the provided answer is √2+√3, let's recheck: 2cos 15° = 2 × 0.9659 = 1.9318, √2+√3 = 1.414+1.732 = 3.146. The provided solution in image: 2cos(π/12) = √2(1+cos(π/6)) = √2(1+√3/2) = √2+√6/2. The image shows √2+√3 as the final result, likely a typo in the source book's option or calculation).