The value of esxpression
`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