If the difference between the roots of (x^2+(a-2)x+a=0) is (3), what is the value of (a)?
Answer and explanation
Correct answer: (4+\sqrt{21}) or (4-\sqrt{21})
Put ((\alpha-\beta)^2=9) in ((\alpha-\beta)^2=(\alpha+\beta)^2-4\alpha\beta). This gives (a^2-8a-5=0), so (a=4\pm\sqrt{21}).
Frequently asked questions
What is the correct answer to this question?
(4+\sqrt{21}) or (4-\sqrt{21})
Why is this the correct answer?
Put ((\alpha-\beta)^2=9) in ((\alpha-\beta)^2=(\alpha+\beta)^2-4\alpha\beta). This gives (a^2-8a-5=0), so (a=4\pm\sqrt{21}).
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Quadratic Equations. Topic: Roots of a Quadratic Equation.
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