2cos(π24)=?2cos(π24)=?
A. 2+2+2–√−−−−−−√−−−−−−−−−−−√2+2+2
B. 2−2+3–√−−−−−−√−−−−−−−−−−−√2−2+3
C. 2−2+2–√−−−−−−√−−−−−−−−−−−√2−2+2
D. 2+2+3–√−−−−−−√ −−−−−−−−−−−√ 2+2+3
সঠিক উত্তরঃ
D.
2+2+3–√−−−−−−√ −−−−−−−−−−−√ 2+2+3
Explanation: 4cos2(π24)−−−−−−−−√=2(1+cosπ12)−−−−−−−−−−√=2+4cos2π12−−−−−−−√−−−−−−−−−−−−√=2+2(1+cosπ6)−−−−−−−−−−√−−−−−−−−−−−−−−−√