If \(\alpha\) and \(\beta\) are the roots of the quadratic equation \(x^2-8x+12=0\), what is the value of \(\alpha^2\beta^2\)?
Answer and explanation
Correct answer: 144
For a quadratic equation \(ax^2+bx+c=0\), the product of its roots is \(\alpha\beta=\frac{c}{a}\). Here, \(a=1\) and \(c=12\), so \(\alpha\beta=12\). Therefore, \(\alpha^2\beta^2=(\alpha\beta)^2=12^2=144\). Option 12 is only the value of \(\alpha\beta\), not its square. Exam tip: Remember that the sum and product of the roots are \(-\frac{b}{a}\) and \(\frac{c}{a}\), respectively.
Frequently asked questions
What is the correct answer to this question?
144
Why is this the correct answer?
For a quadratic equation \(ax^2+bx+c=0\), the product of its roots is \(\alpha\beta=\frac{c}{a}\). Here, \(a=1\) and \(c=12\), so \(\alpha\beta=12\). Therefore, \(\alpha^2\beta^2=(\alpha\beta)^2=12^2=144\). Option 12 is only the value of \(\alpha\beta\), not its square. Exam tip: Remember that the sum and product of the roots are \(-\frac{b}{a}\) and \(\frac{c}{a}\), respectively.
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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