[" 20.Prove that "],[qquad (i)2sin(5 pi)/(12)sin(pi)/(12)=(1)/(2)]

Prove that; 2(sin(5 pi))/(12)(sin pi)/(12)=(1)/(2)

"sin" pi/12 "sin" (5pi)/12=

Prove that (i) " 2sin " (5pi)/(12) " sin " (pi)/(12)=(1)/(2) (ii) " 2 cos " (5pi)/(12) " cos " .(pi)/(12)=(1)/(2) (iii) " 2 sin ".(5pi)/(12) " cos " (pi)/(2) = ((2+sqrt(3))/(2))

Prove that (i) " 2sin " (5pi)/(12) " sin " (pi)/(12)=(1)/(2) (ii) " 2 cos " (5pi)/(12) " cos " .(pi)/(12)=(1)/(2) (iii) " 2 sin ".(5pi)/(12) " cos " (pi)/(2) = ((2+sqrt(3))/(2))

Prove that; 2sin((5pi)/12)sin(pi/12)=1/2

Prove that 2sin((5 pi)/(12))cos((pi)/(12))=(2+sqrt(3))/(2)

Prove that 2"sin"(5pi)/(12)"cos"(pi)/(12)=(sqrt3+2)/2

2sin((5pi)/12) sin(pi/12)=.........

Prove that :cos((pi)/(12))-sin((pi)/(12))=(1)/(sqrt(2))