Prove that: `108sinpi/(18)-144sin^3pi/(18)=18`

Prove that: 108(sin pi)/(18)-144(sin^(3)pi)/(18)=18

Prove that: (sin^(2)pi)/(18)+(sin^(2)pi)/(9)+(sin^(2)(7 pi))/(18)+(sin^(2)(4 pi))/(9)=2

Prove that: sin^2pi/(18)+sin^2pi/9+sin^2(7pi)/(18)+sin^2(4pi)/9=2

Prove that: sin^2pi/(18)+sin^2pi/9+sin^2(7pi)/(18)+sin^2(4pi)/9=2

Prove that: i) sin(5pi)/(18) - cos(4pi)/(9) = sqrt(3)sinpi/9 ii) cos(3pi)/4+A-cos((3pi)/(4)-A)=-sqrt(2)sinA

Prove that: i) sin(5pi)/(18) - cos(4pi)/(9) = sqrt(3)sinpi/9 ii) cos(3pi)/4+A-cos((3pi)/(4)-A)=-sqrt(2)sinA

Prove that: sin^2(pi/(18))+sin^2(pi/9)+sin^2((7pi)/(18))+sin^2((4pi)/9)=2

Prove that, sin^(2)((pi)/(18))+sin^(2)((pi)/(9))+sin^(2)((7pi)/(18))+sin^(2)((4pi)/(9))=2

Prove that "sin"^(2)(pi)/(18)+"sin"^(2)(pi)/(9)+"sin"^(2)(7pi)/(18)+"sin"^(2)(4pi)/(9)=2 .

Prove that sin^2(pi/18)+sin^2(pi/9)+sin^2(7pi/18)+sin^2(4pi/9)=2