If \(a=-4\), which point on the number line is represented by \(\sqrt{a^2}\)?
Answer and explanation
Correct answer: 4
Since \(\sqrt{a^2}=|a|\), substituting \(a=-4\) gives \(\sqrt{(-4)^2}=\sqrt{16}=4\). Therefore, the represented point is 4. Option A is incorrect because the principal square root is never negative, while 16 is only the value of \(a^2\). Exam tip: rewrite \(\sqrt{a^2}\) as \(|a|\) before substituting the value of \(a\).
Frequently asked questions
What is the correct answer to this question?
4
Why is this the correct answer?
Since \(\sqrt{a^2}=|a|\), substituting \(a=-4\) gives \(\sqrt{(-4)^2}=\sqrt{16}=4\). Therefore, the represented point is 4. Option A is incorrect because the principal square root is never negative, while 16 is only the value of \(a^2\). Exam tip: rewrite \(\sqrt{a^2}\) as \(|a|\) before substituting the value of \(a\).
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Polynomials. Topic: Representing real numbers on the number line.
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