Value of expression `sin(pi/9)+sin((2pi)/9)+sin((3pi)/9)+...+sin((17pi)/9)=`

The value of the expression 2^199 sin (pi/199)sin((2pi)/199)sin((3pi)/199)………..sin((198pi)/199))=

The value of the expression 2^199 sin (pi/199)sin((2pi)/199)sin((3pi)/199)………..sin((198pi)/199))=

The value of sin(pi/18)+sin(pi/9)+sin((2pi)/9)+sin((5pi)/18) is

The value of sin((pi)/(18))+sin((pi)/(9))+sin((2pi)/(9))+sin((5pi)/(18)) is

3sin(pi/9) - 4sin^(3)(pi/9) = .......

The value of sin(pi/14)sin((3pi)/14)sin((5pi)/14)sin((7pi)/14)sin((9pi)/14)sin((11pi)/14)sin((13pi)/14) is

Prove that sin ""(pi)/(9) sin ""(2pi)/(9) sin ""( 3pi)/(9) sin ""(4pi)/(9) = (3)/(16).

sin^(-1)(sin((9pi)/4))