सिद्ध करें किsin^(2)10^(@)+sin^(2)20^(@)+sin^(2)30^(@)+sin^(2)40^(@)+sin^(2)50^(@)+sin^(2)60^(@)...

The value of the expression sin^(2)1^(@)+sin^(2)11^(@)+sin^(2)21^(@)+ sin^(2)31^(@)+sin^(2)41^(@)+sin^(2)45^(@)+ sin^(2)49^(@)+sin^(2)59^(@)+sin^(2)69^(@)+ sin^(2)79^(@)+sin^(2)89^(@) is :

sin20^(@)sin40^(@)sin60^(@)sin80^(@)

Find the value of the following: (i) "sin"^(2)30^(@)+"sin"^(2)45^(@)+"sin"^(2)60^(@)+"sin"^(2)90^(@) (ii) 2"sin"^(2)30^(@)-3cos^(2)45^(@)+cos^(2)60^(@)

Find sin20^(@)sin40^(@)sin60^(@)sin80^(@) .

sin10^(@)sin30^(@)sin50^(@)sin70^(@)sin90^(@)=

sin^(2)5^(@)+sin^(2)10^(@)+sin^(2)15^(@)+ .....+sin^(2)85^(@)+sin^(2)90^(@) is equal to

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

sin 20^(@) sin 40^(@) sin 60^(@) sin 80^(@) =(3)/(16)