If (\alpha,\beta) are roots of (x^2+mx+n=0), (\alpha-\beta=4), and (\alpha\beta=5), what is (m^2)?
Answer and explanation
Correct answer: (36)
Use ((\alpha-\beta)^2=(\alpha+\beta)^2-4\alpha\beta). Since (16=(\alpha+\beta)^2-20), we get ((\alpha+\beta)^2=36) and (m^2=36).
Frequently asked questions
What is the correct answer to this question?
(36)
Why is this the correct answer?
Use ((\alpha-\beta)^2=(\alpha+\beta)^2-4\alpha\beta). Since (16=(\alpha+\beta)^2-20), we get ((\alpha+\beta)^2=36) and (m^2=36).
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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