If \(a=-2\), what type of statement does \((a+2)x^2+(a^2-4)x+7=0\) become?
Answer and explanation
Correct answer: Contradictory statement
Substituting \(a=-2\) gives \(a+2=0\) and \(a^2-4=4-4=0\). Therefore, the expression becomes \(0x^2+0x+7=0\), or \(7=0\). Since this statement is impossible, it is contradictory. Exam tip: when the coefficients of all variable terms become zero, classify the remaining constant statement rather than calling it linear or quadratic.
Frequently asked questions
What is the correct answer to this question?
Contradictory statement
Why is this the correct answer?
Substituting \(a=-2\) gives \(a+2=0\) and \(a^2-4=4-4=0\). Therefore, the expression becomes \(0x^2+0x+7=0\), or \(7=0\). Since this statement is impossible, it is contradictory. Exam tip: when the coefficients of all variable terms become zero, classify the remaining constant statement rather than calling it linear or quadratic.
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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