Prove that `4sin(pi/10) sin((13pi)/10)=-1`

sinpi/10+sin(13pi)/(10)=?

Prove that: sin((pi)/(10))sin((13 pi)/(10))=-(1)/(4)

Prove that: sin(9pi)/(10) + sin(13pi)/(10)=-1/2

sin((pi)/(10))sin((3pi)/(10))=?

Prove that: (sin pi)/(10)+(sin(13 pi))/(10)=-(1)/(2)

Prove that: sin((pi)/(14))sin((3 pi)/(14))sin((5 pi)/(14))sin((7 pi)/(14))sin((9 pi)/(14))sin((11 pi)/(14))sin((13 pi)/(14))=(1)/(64)

Prove that "sin"(pi)/(14)"sin"(3pi)/(14)"sin"(5pi)/(14)"sin"(7pi)/(14)=(1)/(8)

prove that sin((pi)/(4)+x)+sin((pi)/(4)-x)=sqrt(2)cos x

Find the value of (a) sin(pi)/(10).sin(13pi)/(10) (b) cos^(2)48^(@)-sin^(2) 12^(@)

The value of sin((pi)/(10))sin((13 pi)/(10)) is