`sin 70^@ - cos 40^(@) =`

sin 10^(@) + sin 20^(@) + sin 40^(@) + sin 50^(@) - sin 70^(@) - sin 80^(@) =

sin 40^(@) - cos 50^(@)= _________

Prove that cos 80^(@) - cos 40^(@) + sqrt3 cos 70^(@) = 0

Find sin 20^@ -cos 70^@ .

sin 10^(@)+sin 20^(@) + sin 40 ^(@) + sin 50 = A) sin 15^(@) +sin 75^(@) B) cos 15^(@) + cos75^(@) C) sin 70^(@) + sin 80^(@) D) cos 70^(@) + cos 80^(@)

sin 70^(@)cos 10^(@) - cos 70^(@) sin 10^(@) = _________

The value of (sin 20^(@) cos 70^(@)+sin70^(@) cos 20^(@) ) is ……….. .

If : sin 40^(@)-cos 70^(@)= k * cos 80^(@), "then" : k = A) sqrt1 B) sqrt2 C) sqrt3 D) sqrt4