Nature of Roots

IMPORTANT

Nature of Roots: Overview

This topic covers concepts, such as, Real and Imaginary Roots of a Quadratic Equation, Rational & Irrational Roots of a Quadratic Equation, Integral Roots of a Quadratic Equation & Conjugate Irrational Roots of a Quadratic Equation etc.

Important Questions on Nature of Roots

HARD
IMPORTANT

Let a, b, c be the sides of a triangle. No two of them are equal and λR. If the roots of the equation x2+2a+b+cx+3λab+bc+ca=0 are real, then

HARD
IMPORTANT

The smallest value of k, for which both the roots of the equation, x2-8kx+16k2-k+1=0 are real, distinct and have value atleast 4, is

HARD
IMPORTANT

If  x2+(ab)x+(1ab)=0,  a,bR then find the values of a for which equation has unequal real roots for all values of b.

HARD
IMPORTANT

If   a,b,c are the sides of a triangle ABC such that   x 2 2( a+b+c )x+3λ( ab+bc+ca )=0 has real roots, then –

MEDIUM
IMPORTANT

If the minimum value of f( x )= x 2 +2bx+2 c 2 is greater than the maximum value of g( x )= x 2 2cx+ b 2 , then (x being real)

MEDIUM
IMPORTANT

Let a, b, c be real number such that  4a+2b+c=0 and ab>0, then the quadratic equation a x 2 +bx+c=0 has –

HARD
IMPORTANT

Let px be a quadratic polynomial with real coefficients. If px=0 has only purely imaginary roots, then the zeroes of the polynomial ppx are

MEDIUM
IMPORTANT

If the roots of the quadratic equation x2+8x+μ2+6μ=0 are real, then μ lies between

HARD
IMPORTANT

Define a function fx=16x2-96x+153x-3 for all real x3. The least positive value of fx is

MEDIUM
IMPORTANT

The number of integral values of m for which the equation 1+m2x2-21+3mx+1+8m=0 has no real root, is

HARD
IMPORTANT

The sum of the abscissae of the points where the curves, y=kx2+(5k+3)x+6k+5, (kR) touch the X-axis, is equal to

EASY
IMPORTANT

If 2+i3 is a root of the equation x2+px+q=0, then the value of (p, q) is

EASY
IMPORTANT

If the equation x2- 2+mx+m2-4m+4=0 has coincident roots, then-

HARD
IMPORTANT

If c + 1 < b, then the roots of the quadratic equation x2 - bx + c = 0 is 

EASY
IMPORTANT

The number of real roots of the equation x - 12+x - 22+x - 32=0 is -

HARD
IMPORTANT

How many ordered pairs of integers (x, y) satisfy the equation x2+y2=2(x+y)+xy?

MEDIUM
IMPORTANT

For x, the given expression x2+34x-71x2+2x-7, cannot lie between a and b. Find a+b.

MEDIUM
IMPORTANT

Prove that if the roots of the equation a4+b4x2+4abcdx+c4+d4=0 be real, then they cannot be unequal.

EASY
IMPORTANT

If the roots of the equation x2-2a+bx+aa+2b+c=0 be equal, prove that a,b,c are in geometric progression.

HARD
IMPORTANT

If the roots of the equation ab-cx2+bc-ax+ca-b=0 are equal, then prove that 1a+1c=2b.