If `|a|,|b|,|c| lt 1` and `a,b,c` are in A.P, let `S_x=1+x+x^2+...oo` then `S_a, S_b, S_c` are in
(A) A.P (B) G.P (C)H.P (D) None

If a,b,c are in A.P ,then 3^(a),3^(b),3^(c) shall be in (A) A.P (B) G.P (C) H.P (D) None of these

In triangle ABC, if cosA+2cosB+cosC=2,t h e na ,b ,c 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^2+2bx+c=0 and a_1x^2+2b_1x+c_1=0 have a common root and a/a_1,b/b_1,c/c_1 are in AP then a_1,b_1,c_1 are in (A) A.P. (B) G.P. (C) H.P. (D) none of these

If x,y,z are in A.P. then : yz,zx,xy are in (a) A.P (b) G.P (c) H.P (d) no definite sequence

If a,b,c are in A.P and a,b,d are in G.P, prove that a,a-b,d-c are in G.P.

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

If x,y,z are in A.P. then : e^(-x), e^(-y),e^(-z) are in (a) A.P (b) G.P (c) H.P (d) no definite sequence

If a,b,c are in A.P. as well as in G.P. then

If |[x+a, y+b, z+c] , [y+b, z+c, x+A] , [z+c, x+a, y+b]|=0 and a+c=-b then x,-y/2,z are in (A) A.P. (B) G.P. (C) H.P. (D) None of these