k k κ? +k+1 κ? +k κ2 1 1. If U,= 2η 2η -1 then k = and Συ, = 72, η =1 (a) 8 (c) 6 (6) 9 (d) none of these

If tan 69^(@) + tan 66^(@) - tan 69^(@)tan 66^(@) = 2k then k = (a) -(1)/(2) (b) (1)/(2) (c) -1 (d)None of these

If D_k=|[1, n, n];[ 2k, n^2+n+1, n^2+n];[ 2k-1, n^2, n^2+n+1]|a n dsum_(k=1)^n D_k=56. then n equals (a) 4 (b) 6 (c) 8 (d) none of these

sum_(k=1)^m(k^2+1)k=2009xx2010!, then m= (A) 2009 (B) 2010 (C) 2011 (D) none of these

sum_(k=1)^m(k^2+1)k=2009xx2010!, then m= (A) 2009 (B) 2010 (C) 2011 (D) none of these

If x is real and k=(x^(2)-x+1)/(x^(2)+x+1), then k in[1/3,3] (b) k>=3(c)k<=1/3(d) none of these

If D_k=|[1,n,n],[2k,n^2+n+2,n^2+n],[2k-1,n^2,n^2+n+2]| and sum_(k=1)^n D_k=48 ,then n equals (a) 4 (b) 6 (c) 8 (d) none of these

If D_k=|[1,n,n],[2k,n^2+n+2,n^2+n],[2k-1,n^2,n^2+n+2]| and sum_(k=1)^n D_k=48 ,then n equals (a)4 (b) 6 (c) 8 (d) none of these

If (k-1),(2k+1),(6k+3) are in GP then k=?

If cos3x+sin(2x-(7pi)/6)=-2 , then x is equal to (k in Z) pi/3(6k+1) (b) pi/3(6k-1) pi/3(2k+1) (d) none of these

D_ (k) = | 2 ^ (k-1) (1) / (k (k + 1)) sin k theta xyz2 ^ (n) -1 (n) / (n + 1) (sin ((n +) 1) / (2) theta (sin n) / (2) theta) / (sin theta) / 2, thensum_ (k = 1) (n) D_ (k)