JEE MATHEMATICS MCQ: QUADRATIC EQUATIONS

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Analyzing +4 | -1

If the equation,

x^{2}+b x+45=0(b \in R)

has conjugate complex roots and they satisfy

|z+1|=2 \sqrt{10}

, then:
]

View answer and explanation

Correct option: A

b^{2}-b=30

Option A (

b^{2}-b=30

) is correct because by using the given condition

|z+1|=2 \sqrt{10}

and the properties of complex conjugate roots, we can find the value of b and then calculate

b^{2}-b

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