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    The roots of the equation ax2+x+b=0ax^2+x+b=0ax2+x+b=0​ are equal if:
    Question

    The roots of the equation ax2+x+b=0ax^2+x+b=0​ are equal if:

    A.

    ab=14ab=\frac{1}{4}​​

    B.

    b2<4ab^2<4a​​

    C.

    b2>4ab^2>4a​​

    D.

    b2=4ab^2=4a​​

    Correct option is A

    Given:
    The quadratic equation:
    ax2+x+b=0ax^2 + x + b = 0​​
    Concept Used:
    For a quadratic equation ax2+bx+c=0,ax^2 + bx + c = 0,​ the roots are equal if the discriminant is zero. The discriminant D for this equation is given by:
    D=b24acD = b^2 – 4ac​​
    Solution:
    From equation ax2+x+b=0ax^2 + x + b = 0​, we have:
    D = b24ac=124abb^2 – 4ac = 1^2 - 4 \cdot a \cdot b​​
    D = 1 − 4ab
    For the roots to be equal, the discriminant must be zero:
    D = 0
    1−4ab = 0
    4ab = 1
    ab = 14\frac{1}{4}​​
    Thus, ab = 14.\bf\frac{1}{4}.​​

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