Prove that
`sin 20^(@) + sin 140^(@)-cos 10 ^(@) =0`

Prove that (sin20^(@) + sin40^(@)) + (cos20^(@) + cos40^(@))=(sqrt(3)+1)cos10^(@)

Prove that (sin20^(@) + sin40^(@)) + (cos20^(@) + cos40^(@))=(sqrt(3)+1)cos10^(@)

Prove that, (cos 20^(@) + sin 20^(@))/(cos 20^(@) - sin 20^(@)) = tan 65^(@)

Prove that (i) sin 70^(@) cos 10^(@) -cos 70^(@) sin 10^(@) =(sqrt(3))/(2) (ii) cos 50^(@) cos 10^(@) -sin 50^(@) sin 10^(@) =(1)/(2) (ii) cos 80^(@) cos 20^(@) + sin 80^(@) sin 20^(@) =(1)/(2) (iv) sin 36^(@) cos 9^(@) + cos 36^(@) sin 9^(@) =(1)/(sqrt(3))

Prove that : sin 10^(@) + sin 20^(@) + sin 40^(@) + sin 50^(@) = sin 70^(@) + sin 80^(@).

Prove that sin 80^(@) cos20^(@) + sin45^(@) cos145^(@)+sin 55^(@) cos245^(@) = 0

Prove that sin10^(@) + sin20^(@) + sin 40^(@) + sin 50^(@) = sin 70^(@) + sin 80^(@)

Prove that: cos20^(@)+cos100^(@)+cos140^(@)=-0

Prove that cos32^(@) sin20^(@) + cos144^(@) cos2^(@) + sin68^(@) cos56^(@) = 0

Prove that sin10^(@)+sin20^(@)+sin40^(@)+sin50^(@)=sin70^(@)+sin80^(@) .