If n and r are positive integers such that`0ltrltn` then show that the roots of the quadratic equation`nC_r x^2+2. ^nC_(r+1)x+^nC_(r+2)=0` are real.

Show that the roots of the equation x^3 +px^2 +qx +r=0 are in H.P then 2q^3 =9r (pq-3r)

Show that the roots of the equation x^3 +px^2 +qx +r=0 are in A.P 2p^3 - 9 pq + 27 r=0

If p , q , ra n ds are real numbers such that p r=2(q+s), then show that at least one of the equations x^2+p x+q=0 and x^2+r x+s=0 has real roots.

If p, q, r each are positive rational number such tlaht p gt q gt r and the quadratic equation (p + q - 2r)x^(2) + (q + r- 2p)x + (r + p - 2q) = 0 has a root in (-1 , 0) then which of the following statement hold good? (A) (r + p)/(q) lt 2 (B) Both roots of given quadratic are rational (C) The equation px^(2) + 2qx + r = 0 has real and distinct roots (D) The equation px^(2) + 2qx + r = 0 has no real roots

If a, b, c in R and the quadratic equation x^2 + (a + b) x + c = 0 has no real roots then

If p ,q ,r are positive and are in A.P., the roots of quadratic equation p x^2+q x+r=0 are all real for a. |r/p-7|geq4sqrt(3) b. |p/r-7|geq4sqrt(3) c. all p and r d. no p and r

Minimum possible number of positive root of the quadratic equation x^2 -(1 +lambda)x+ lambda -2 =0 , lambda in R

If alpha and beta are the roots of the quadratic equation 4x ^(2) + 2x -1=0 then the value of sum _(r =1) ^(oo) (a ^(r ) + beta ^(r )) is :

Column I, Column II If a ,b ,c ,a n dd are four zero real numbers such that (d+a-b)^2+(d+b-c)^2=0 and he root of the equation a(b-c)x^2+b(c-a)x=c(a-b)=0 are real and equal, then, p. a+b+c=0 If the roots the equation (a^2+b^2)x^2-2b(a+c)x+(b^2+c^2)=0 are real and equal, then, q. a ,b ,ca r einAdotPdot If the equation a x^2+b x+c=0a n dx^3-3x^2+3x-0 have a common real root, then, r. a ,b ,ca r einGdotPdot Let a ,b ,c be positive real number such that the expression b x^2+(sqrt((a+b)^2+b^2))x+(a+c) is non-negative AAx in R , then, s. a ,b ,ca r einHdotPdot

If for positive integers r gt 1, n gt 2 , the coefficients of the (3r) th and (r+2) th powers of x in the expansion of (1+x)^(2n) are equal, then prove that n=2r+1 .