If `a,b,c,d,e,x` are real and `(a^2+b^2+c^2+d^2)x^2-2(ab+bc+cd+de)x+(b^2+c^2+d^2+e^2)le0` then a,b,c,d,e are in (A) A.P. (B) G.P. (C) H.P. (D) none of these

If a,b,c,d, x are real and the roots of equation (a^2+b^2+c^2)x^2-2(ab+bc+cd)x+(b^2+c^2+d^2)=0 are real and equal then a,b,c,d are 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

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

Let a,b,c be positive real numers such that bx^2+(sqrt(((a+c)^2+4b^2))x +(a+c),=0, AA x epsilon R, then a,b,c are in (A) G.P. (B) A.P. (C) H.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 a,b,c,d,e are in H.P., then a/(b+c+d+e), b/(a+c+d+e),c/(a+b+d+e), d/(a+b+c+e), e/(a+b+c+d) are in (A) A.P. (B) G.P. (C) H.P. (D) none of these

If a,b,c,d are such unequal real numbers that (a^(2)+b^(2)+c^(2))p^(2)-2 (ab+bc+cd) p+ (b^(2)+c^(2)+d^(2)) le 0 then a,b,c, d are in -

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

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 a, b,c be the sides foi a triangle ABC and if roots of equation a(b-c)x^2+b(c-a)x+c(a-b)=0 are equal then sin^2 A/2, sin^2, B/2, sin^2 C/2 are in (A) A.P. (B) G.P. (C) H.P. (D) none of these