If `sum_(r=15)^29(cos(rpi/2+theta)=S_1` and `sum_(r=15)^29(sin(rpi/2+theta)=S_2`, then `S_1/S_2` equals

If sum_(r=15)^(29)(cos(r(pi)/(2)+theta)=S_(1) and sum_(r=15)^(29)(sin(r(pi)/(2)+theta)=S_(2), then (S_(1))/(S_(2)) equals

If sum_(r=15)^(29)cos((r pi)/(2)+theta)=S_(1) and sum_(r=15)^(29)sin((r pi)/(2)+theta)=S_(2) then find the value of (s_(2))/(s_(1))

Find sum_(r=1)^(10) cos^(3) rpi/3 .

Prove that sum_(r=1)^(10) = sin^(2) rpi/18 =5 .

Find the value of sum_(r=1)^(n-1)"sin"^(2)(rpi)/(n)

Let S= sum_(r=1)^(5) cos (2r-1) (pi)/(11) and P=Pi_(r=1)^(4) cos (2^(r). (pi)/(15)) , then

Let S= sum_(r=1)^(5) cos (2r-1) (pi)/(11) and P=Pi_(r=1)^(4) cos (2^(r). (pi)/(15)) , then

Let S= sum_(r=1)^(5) cos (2r-1) (pi)/(11) and P=Pi_(r=1)^(4) cos (2^(r). (pi)/(15)) , then

sum_(r=0)^(n) sin^(2)""(rpi)/(n) is equal to