योग `underset(k=1)overset(20)Sigma k (1)/(2^(k))` बराबर है

Evaluate underset(k=1)overset(11)Sigma (2 + 3^(k))

Let S_n=underset(k=1)overset(4n)Sigma (-1)^((k(k+1))/2)k^2 .Then S_n can take value (s)

Let S_n=underset(k=1)overset(4n)Sigma (-1)^((k(k+1))/2)k^2 .Then S_n can take value (s)

If underset(k = 1)overset(n)sumtan^(-1)((1)/(k^(2)+k+1))= tan^(-1)(theta) , " then " theta =

The value of underset(k=1) overset(13)Sigma(1)/(sin ((pi)/(4)+(k-1)pi)/(6)sin((pi)/(4)+(kpi)/(6)) is equal to

The value of cot[underset(n=1)overset(100)Sigmacot^(-1)(1+underset(k=1)overset(n)Sigma2k)] is

The value of cot[underset(n=1)overset(100)Sigmacot^(-1)(1+underset(k=1)overset(n)Sigma2k)] is