Question

cos 10 ° + cos 20 °+ ...cos 80 ° please find it and I'll mark the correct one as brainliest...​

Answer 1

Answer:

cos 10 + cos 20+ cos 30+ cos 40+ cos 50 + cos 60+ cos 70+ cos 80

cos10 + cos 80 + cos 20 + cos 70 + cos 30 + cos 60 + cos 40 + cos 50

2 cos 10 + 2 cos 20 +2 cos 30 + 2 cos 40 --------as ( cos A = sin (90-A) )

2(cos 10 + cos 20 +cos 30+cos 40) or 2(sin 50 +sin 60 +sin 70 + sin 80)

 I think this will be only or if it is further i am sorry I don't know further calculations