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, Conjugate Imaginary Roots of Quadratic Equation, Nature of Roots of 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 –

MEDIUM
IMPORTANT

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

MEDIUM
IMPORTANT

Find all the integral values of a for which the quadratic equation x-ax-10+1=0 has integral roots.

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.

EASY
IMPORTANT

If the roots of the equation qx2-px+q=0 be a real show that p cannot lie between -2q and 2qq>0.

MEDIUM
IMPORTANT

If the roots of the equation qx2+2px+2q=0 are real and unequal, prove that the roots of the equation p+qx2+2qx+p-q=0 are imaginary.

MEDIUM
IMPORTANT

If the roots of the equations qx2+px+q=0 be imaginary, show that the roots of the equation x2-4qx+p2=0 are real and unequal.

EASY
IMPORTANT

If a, b, c are three rational numbers and if 2 is a root of the quadratic equation ax2+bx+c=0, what is the vlaue of b?

EASY
IMPORTANT

Verify that the discriminant of the quadratic equation x2-25x+1=0, is a perfect square, yet its roots are not conjugate surds. Explain the reason behind.

EASY
IMPORTANT

Verify that for the equation x2-5ix-6=0, the roots are not conjugate imaginary numbers. Explain the reason

EASY
IMPORTANT

Find the nature of roots of the following equations without determining the roots :

32ix2+4x+3i2=0

EASY
IMPORTANT

Find the nature of roots of the following equations without determining the roots :

78x2-x+27=0

EASY
IMPORTANT

Find the nature of roots of the following equations without determining the roots :

2x2-26x+3=0