Prove that: `s inpi/5s in(2pi)/5s in(3pi)/5s in(4pi)/5=5/(16)`

Prove that: "sin"(pi)/(5)"sin"(2pi)/(5)"sin"(3pi)/(5)"sin"(4pi)/(5)=(5)/(16) "sin"36^(@) "sin"72^(@) "sin"108^(@) sin 144^(@)=(5)/(16) .

Prove that: (sin pi)/(5)(sin(2 pi))/(5)(sin(3 pi))/(5)(sin(4 pi))/(5)=(5)/(16)

Prove that: 2cos (pi)/(13) cos (9 pi)/(13)(3 pi)/(13)(5 pi)/(13)=0

Prove that: 2(sin pi)/(6)sec(pi)/(3)-4(sin(5 pi))/(6)(cos pi)/(4)=1

Prove that: sin((3pi)/(8)-5)cos((pi)/(8)+5)+cos((3pi)/(8)-5)sin((pi)/(8)+7)=1

Prove that: (s in5A-s in3A)/(cos5A+cos3A)=tan A

Prove that: (cos pi)/(5)(cos(2 pi))/(5)(cos(4 pi))/(5)(cos(8 pi))/(5)=(-1)/(6)

Prove that quad quad 3sin(pi)/(6) sec (5 pi)/(6)(5 pi)/(6)(pi)/(4)=1