Prove that : `tan\ pi/7*tan\ (2pi)/7*tan\ (3pi)/7=sqrt(7)`

Show that: (tan^2\ pi/7+tan^2\ (2pi)/7+tan^2\ (3pi)/7)(cot^2\ pi/7 +cot^2\ (2pi)/7+ cot^2\ (3pi)/7)=105

Show that : sin pi/7 *sin 2pi/7* sin3pi/7 = sqrt7/8

Prove that: tan(pi/6).tan(pi/3)=tan(pi/4)

Prove that : tan^2 (pi/4)+tan^2(pi/4)+tan^2(pi/3)=13/3

Prove that: (tan(pi/4+A)+tan(pi/4-A))/(tan(pi/4+A)-tan(pi/4-A))="cosec"2A

Prove that: sinpi/7+sin(2pi)/(7) + sin(8pi)/7 + sin(9pi)/7=0

Prove that tan ((pi) / (12)) * tan (5 (pi) / (12)) * tan (7 (pi) / (12)) * tan (11 (pi) / (12)) = 1

Statement-l : tan((6pi)/7)-tan((5pi)/7)-tan(pi/7)=tan((6pi)/7).tan((5pi)/7).tan(pi/7). because Statement-2:If theta=alpha+beta, then tan theta-tan alpha-tan beta= tan theta.tanalpha. tan beta.

Find the value of tan. pi/20tan. (3pi)/20tan. (5pi)/20tan. (7pi)/20tan. (9pi)/20 .

Show that: sin((2pi)/7)+ sin ((4pi)/7) + sin( (8pi)/7) = sqrt7/2 .