JEE 2023 — Mathematics PYQ
JEE | Mathematics | 202396cos33πcos332πcos334πcos338πcos3316π
Choose the correct answer:
- A.
4
- B.
2
- C.
3
(Correct Answer) - D.
1
3
Explanation
cosAcos2Acos4A…cos(2n−1A)=2nsinAsin(2nA)
Yahan A=33π aur n=5 hai.
=96[25sin33πsin(25⋅33π)]
=96[32sin33πsin3332π]
Ab, sin3332π ko ham sin(π−33π) likh sakte hain:
=3296[sin33πsin(π−33π)]
=3[sin33πsin33π]
=3×1=3
Explanation
cosAcos2Acos4A…cos(2n−1A)=2nsinAsin(2nA)
Yahan A=33π aur n=5 hai.
=96[25sin33πsin(25⋅33π)]
=96[32sin33πsin3332π]
Ab, sin3332π ko ham sin(π−33π) likh sakte hain:
=3296[sin33πsin(π−33π)]
=3[sin33πsin33π]
=3×1=3