If `S` be the focus and `R` the point of intersection of the tangents to a parabola at two points `P and Q`, then `PS, RS and QS` are in : (A) A.P. (B) G.P. (C) H.P. (D) none of these

If tangents at A and B on the parabola y^2 = 4ax , intersect at point C , then ordinates of A, C and B are 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 the numbers p,q,r are in A.P. then m^(7p), m^(7q), m^(7r)(mgt0) are in (A) A.P. (B) G.P. (C) H.P. (D) none of these

If the square of differences of three numbers be in A.P., then their differences re in (A) A.P. (B) G.P. (C) H.P. (D) none of these

If (b+c)/(a+d)= (bc)/(ad)=3 ((b-c)/(a-d)) then a,b,c,d are in (A) H.P. (B) G.P. (C) A.P. (D) none of these

If a,b,c,d are distinct positive then a^n/b^ngtc^n/d^n for all epsilon N if a,b,c,d are in (A) A.P. (B) G.P. (C) H.P. (D) none of these

If normals at two points A(x_1, y_1) and B(x_2, y_2) of the parabola y^2 = 4ax , intersect on the parabola, then y_1, 2sqrt(2)a, y_2 are in (A) A.P. (B) G.P. (C) H.P. (D) none of these

If cos A+cos B+2cos C=2 then the sides of the A B C are in (a)A.P. (b) G.P. (c) H.P. (d) none

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

|(a+1, a+2, a+p), (a+2, a+3, a+q) ,(a+3, a+4, a+r)|=0 , then p, q r are in (A) A P (B) G P (C) H P (D) none of these