What is the discriminant of the quadratic equation \(ax^2+bx+c=0\)?
Answer and explanation
Correct answer: \(b^2-4ac\)
The discriminant is denoted by \(D\) and is given by \(D=b^2-4ac\). It determines the nature of the roots: two distinct real roots if \(D>0\), one repeated real root if \(D=0\), and two complex conjugate roots if \(D<0\). Option B has the wrong sign (\(+4ac\) instead of \(-4ac\)), while options A and D mix up the coefficients and are not the standard discriminant. Exam tip: correctly identify \(a,b,c\) from the equation and substitute into \(b^2-4ac\) to avoid sign errors.
Frequently asked questions
What is the correct answer to this question?
\(b^2-4ac\)
Why is this the correct answer?
The discriminant is denoted by \(D\) and is given by \(D=b^2-4ac\). It determines the nature of the roots: two distinct real roots if \(D>0\), one repeated real root if \(D=0\), and two complex conjugate roots if \(D<0\). Option B has the wrong sign (\(+4ac\) instead of \(-4ac\)), while options A and D mix up the coefficients and are not the standard discriminant. Exam tip: correctly identify \(a,b,c\) from the equation and substitute into \(b^2-4ac\) to avoid sign errors.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Quadratic Equations. Topic: Introduction to Quadratic Equations.
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