Repeated roots
Repeated roots are two equal roots of a quadratic equation, and they occur when the discriminant is zero.
Practice This ConceptMain explanation
Teacher explanation
When D = 0, the quadratic just touches the x-axis at one point if drawn as a graph. Algebraically, this means the same root appears twice.
Example
x^2 - 6x + 9 = 0 gives the root x = 3 twice.
Simple analogy
Zero discriminant, same answer twice.
Common confusion
Students may write two different values even when the discriminant is zero.
Exam tip
Whenever D = 0, state that the roots are real and equal, not just real.
Answer writing and exam use
1-mark use
Write the exact meaning of repeated roots in one clean line.
2-mark use
Define repeated roots and add one example or condition.
3-mark use
Explain repeated roots, show the method or example, and mention the common mistake.
Practice this concept with focused MCQs
Open the concept quiz intro first, review the test details, and then start a focused MCQ set from this concept only. Instant score and answer review are live now.
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