1+cos56+cos58-cos66

Value of 1 + cos 56^@+ cos 58^@ - cos 66^@ is:

Show that 1+cos 56^(@)+ cos 58^(@)-cos66^(@)=4 cos 28^(@) cos 29^(@) sin 33^(@)

1+cos 56^0 + cos 58^0 - cos 66^0=4cos 28^0 cos 29^0 sin 33^0 .

1+cos 56^0 + cos 58^0 - cos 66^0=4cos 28^0 cos 29^0 sin 33^0 .

(1+ cos 56^(@) + cos 58^(@) - cos 66^(@))/( cos 28^(@) cos 29^@ sin 33^(@) )=

1+ cso 56^(@) + cos 58^(@) - cos 66^(@)=

cos 56 ^(@) + cos 58^(@) - cos 66^(@) - 4 cos 28^(@) cos 29^(@) sin 33 ^(@) =

If A , Ba n dC are the angels of a triangle, show that |[-1+cos B, cos C+cos B, cos B],[ cos C+cos A,-1+cos A ,cos A],[-1+cos B,-1+cos A,-1]|=0

If A , Ba n dC are the angels of a triangle, show that |-1+cos B cos C+cos B cos B cos C+cos A-1+cos A cos A-1+cos B-1+cos A-1|=0