If `a_1,a_2,a_3,a_4` are in H.P. then `1/(a_1 a_4) sum_(r=1)^3 a_r a_(r+1)` is a root of (A) `x^2-2x-15=0` (B) `x^2+2x+15=0` (C) `x^2+2x-15=0` (D) `x^2-2x+15=0`

If a_1,a_2,a_3,a_4 are in HP , then 1/(a_1a_4)sum_(r=1)^3a_r a_(r+1) is root of :

Let f:RrarrR such that f(x) is continuous and attains only rational value at all real x and f(3)=4. If a_1,a_2,a_3,a_4,a_5 are in H.P. then sum_(r=1)^4 a_r a_(r+1)= (A) f(3).a_1a_5 (B) f(3).a_4a_5 (C) f(3).a_1a_2 (D) f(3).a_1a_3

cIf a_1,a_2,a_3,..,a_n in R then (x-a_1)^2+(x-a_2)^2+....+(x-a_n)^2 assumes its least value at x=

If a_1, a_2, a_3,.....a_n are in H.P. and a_1 a_2+a_2 a_3+a_3 a_4+.......a_(n-1) a_n=ka_1 a_n , then k is equal to

Q. If 1.5 0 (b) (2x-3)(2x-9) =0 (d) (2x-3)(2x-9)<=0

If a_0, a_1, a_2, a_3 are all the positive, then 4a_0x^3+3a_1x^2+2a_2x+a_3=0 has least one root in (-1,0) if

a_1, a_2, a_3, in R-{0} and a_1+a_2cos2x+a_3sin^2x=0 for all x in R , then

If p(x),q(x) and r(x) be polynomials of degree one and a_1,a_2,a_3 be real numbers then |(p(a_1), p(a_2),p(a_3)),(q(a_1), q(a_2),q(a_3)),(r(a_1), r(a_2),r(a_3))|= (A) 0 (B) 1 (C) -1 (D) none of these

(1 +x)^15 = a_0 + a_1x +…..+a_15 x^15 rArr sum_(r = 1)^15 r (a_r)/(a_(r - 1)) =

a_1, a_2, a_3, in R-{0} and a_1+a_2cos2x+a_3sin^2x=0fora l lx in R , then