EASY
Earn 100

Find the greatest value of(3-20x-25X2) for real values of x.

Important Questions on Theory of Equation

MEDIUM
The value of λ such that sum of the squares of the roots of the quadratic equation, x2+3-λ x+2=λ has the least value is:
EASY
Let fx=1+b2x2+2bx+1 and mb be the minimum value of fx. As b varies, the range of mb is
MEDIUM
If λR is such that the sum of the cubes of the roots of the equation x2+2-λx+10-λ=0 is minimum, then the magnitude of the difference of the roots of this equation is :
MEDIUM
The integer k, for which the inequality x2-23k-1x+8k2-7>0 is valid for every x in R is:
EASY
Let f:[2,)R be the function defined by f(x)=x2-4x+5, then the range of f is
EASY
If f:R-2R is a function defined by fx=x2-4x-2, then range is
MEDIUM
If y=x2+14x+9x2+2x+3x, then the interval of maximum length in which y lies is
HARD
The number of integral values of m for which the quadratic expression 1+2m x2-21+3mx+41+m, xR is always positive, is
HARD
Let fx=x-ax-b-a+b2. If fx=0 has both non-negative roots, then the minimum value of fx
EASY
Let a, b, c be real numbers such that a+b+c<0 and the quadratic equation ax2+bx+c=0 has imaginary roots. Then
EASY
Let fx be a quadratic polynomial with f2=10 and f-2=-2. Then the coefficient of x in fx is
HARD
If x,y,zR, x+y+z=5, x2+y2+z2=9, then length of interval in which x lies is
HARD
The maximum value of z in the following equation z=6xy+y2, where 3x+4y100 and 4x+3y75 for x0 and y0
is
MEDIUM

Assertion A: 3x2-16x+4>-16 is satisfied for some values of real x in 0,103

Reason R: ax2+bx+c and a will have the same sign for some values of xR when b2-4ac>0

The correct option among the following is

EASY
Suppose a parabola y=ax2+bx+c has two x intercepts, one positive and negative, and its vertex is 2, -2 . Then which of the following is true?
MEDIUM

Consider the figure of real quadratic y=Qx=ax2+bx+c as shown. Select the wrong option (Where D=b2-4ac, i=-1)

Question Image

HARD
If x is real, then x2-2x+4x2+2x+4 takes values in the interval
EASY
The expression y=ax2+bx+c has always the same sign as c if -
EASY
Product of real roots of the equation t2x2+x+9=0
HARD
Let fx=1+b2x2+2bx+1 and mb be the minimum value of fx. As b varies, the range of mb is