I `a_n= int_0^(pi/2) (1-cos2nx)/(1-cos2x)dx then a_1,a_2,a_3,………,a_n` are in (A) A.P. only (B) G.P.only (C) H.P. only (D) A.P., G.P. and H.P.

If a_n= the digit at units palce in the number o 1!+2!+3!+……….n! for nge4 the a_4, a_5, a_6, ……… are in (A) A.P. only (B) G.P. only (C) A.P. and G.P. only (D) A.P., G.P. and H.P.

If a_n= int_0^pi (sin(2n-1)x)/(sinx) dx . Then the number a_1,a_2,a_3 …….. Are in (A) A.P (B) G.P (C) H.P (D) none of these

If a_n= int_0^pi(sin(2n-1)x)/sinx dx, then a_1a_2a_3 are in (A) A.P. (B) G.P. (C) H.P. (D) none of these

If a-b,ax-by,ax^2-by^2a,b!=0) are in G.P., then x,y (ax-by)/(a-b) are in (A) A.P. only (B) G.P.only (C) A.P., G.P. (D) A.P., and G.P and H.P

If a,b,c are non zero real numbers such that 3(a^2+b^2+c^2+1)=2(a+b+c+ab+bc+ca) then a,b,c are in (A) A.P. only (B) G.P. only (C) A.P., G.P., and H.P. (D) A.P. and G.P.both

If cos2B=(cos(A+C))/(cos(A-C)), then tan A,tan B,tan C are in (a)A.P.(b) G.P.(c) H.P.(d) none of these

If x,a_1,a_2,a_3,…..a_n epsilon R and (x-a_1+a_2)^2+(x-a_2+a_3)^2+…….+(x-a_(n-1)+a_n)^2le0 , then a_1,a_2,a_3………a_n are in (A) AP (B) GP (C) HP (D) none of these

If a_1,a_2,a_3……..a_n are in H.P. and f(k) = sum_(r=1)^na_r-a_k then (f(1))/a_1, (f(2))/a_3 ….f(n)/a_n are (A) A.P. (B) G.P. (C) H.P. (D) none of these

If a_1,a_2, a_3………. are in H.P. and f(k) =sum_(r=1)^n a_r-a_k, the a_1/(f(1)), a_2/(f(2)), a_3/(f(3)), …….., a_n/(f(n)) are in (A) A.P. (B) G.P (C) H.P. (D) none of these

If the lines 2x - ay + 1 = 0, 3x – by + 1 = 0, 4x-cy+1 =0 concurrent, then a, b, c are in (A) A.P. (B) G.P. (C) H.P. (D) A.G.P