Question

sin 47 +sin 61-sin 11-sin 25​

Answer 1

Step-by-step explanation:

(sin47-sin25)+(sin61-sin11)

(2cos36×sin 11) + (2cos36×sin25)

2cos36 (sin 11+sin 25)

4cos36 × sin 18 × cos 7

sin18= ( √5-1)4 and cos 36=(√5-1)/4

so on solving we get cos 7

hope it's useful for you