If `a_n=sin((npi)/6)`then the value of `sum a_n^2`

If a_n=sin((npi)/6) then the value of sum _(n=2 )^6 a_n^2

sum_(i=1)^(2n) sin^(-1)(x_i)=npi then the value of sum_(i=1)^n cos^(-1)x_i+sum_(i=1)^n tan^(-1)x_i= (A) (npi)/4 (B) (2/3)npi (C) (5/4)npi (D) 2npi

If n in N, sum_(k=1)^(n)sin^(-1(x_(k))=(npi)/2 then the value of sum_(k=1)^(n)x_(k)=

If a_n=n/((n+1)!) then find sum_(n=1)^50 a_n

If a_n =(2n-3)/6 , then find a_(10) ?

Let A_n be the area bounded by the curve y = x^n(n>=1) and the line x=0, y = 0 and x =1/2 .If sum_(n=1)^n (2^n A_n)/n=1/3 then find the value of n.

In an A.P. if a = – 7.2, d = 3.6, a_n = 7.2, then find the value of n.

a_n=(n-1)(n-2) then a_5 =….

If in an AP a=15, d=-3 and a_n=0 . Then find the value of n.

If a_n=(n(n+1))/2 a_4 =…..