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Mathematics - Quadratic Equation Question with Solution | TestHub

MathematicsQuadratic EquationGraph and Sign of QuadraticEasy2 minPYQ_2024
MathematicsEasysingle choice

LetSbe the set of positive integral values ofafor whichax2+2a+1x+9a+4x2-8x+32<0, x. Then, the number of elements inSis:

Options:

Answer:
B
Solution:

Given:

 ax2+2(a+1)x+9a+4x2-8x+32<0  xR

For quadratic x2-8x+32=0,  D1=-82-432=-64

Since the discriminant is less than zero and the leading coefficient is positive, this quadratic will always be positive.

Now, solving ax2+2(a+1)x+9a+4<0

We know that, for a quadratic to be always negative, the coefficient of x2<0, D<0.

a<0 

But we want positive values.

So, no positive integral value exist.

Stream:JEESubject:MathematicsTopic:Quadratic EquationSubtopic:Graph and Sign of Quadratic
2mℹ️ Source: PYQ_2024

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