Question

34. cos 20° + cos30°+ cos40º =
1) 1-2 sin 10° sin 15° sin 20°
2) cos 20°cos 30° cos 40°
3) 4 cos 10° cos 15º cos 20°
4) 4 cos 25° cos 30° 350​

Answer 1

Huh?

I don't understand your question..........

Sorry................................................................