If \(\alpha\) and \(\beta\) are the roots of the quadratic equation \(x^2-3x-28=0\), what is the value of \((\alpha+1)(\beta+1)\)?
Answer and explanation
Correct answer: -24
By Vieta’s formulas, \(\alpha+\beta=3\) and \(\alpha\beta=-28\). Therefore, \((\alpha+1)(\beta+1)=\alpha\beta+\alpha+\beta+1=-28+3+1=-24\). Hence, option A is correct. Remember to include the final \(+1\) term when expanding the product; omitting it leads to an incorrect result.
Frequently asked questions
What is the correct answer to this question?
-24
Why is this the correct answer?
By Vieta’s formulas, \(\alpha+\beta=3\) and \(\alpha\beta=-28\). Therefore, \((\alpha+1)(\beta+1)=\alpha\beta+\alpha+\beta+1=-28+3+1=-24\). Hence, option A is correct. Remember to include the final \(+1\) term when expanding the product; omitting it leads to an incorrect result.
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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