What are the real roots of the equation \(2x^2-8=0\)?
Answer and explanation
Correct answer: 2 and -2
Divide both sides by 2: from \(2x^2-8=0\) we get \(x^2=4\). Taking square roots gives \(x=\pm 2\), i.e. 2 and −2. Option B would come from incorrectly assuming \(x^2=16\); option C is wrong because 0 does not satisfy the equation; option D is incomplete because it omits the negative root. Exam tip: when taking square roots always include both \(+\) and \(-\) solutions after squaring.
Frequently asked questions
What is the correct answer to this question?
2 and -2
Why is this the correct answer?
Divide both sides by 2: from \(2x^2-8=0\) we get \(x^2=4\). Taking square roots gives \(x=\pm 2\), i.e. 2 and −2. Option B would come from incorrectly assuming \(x^2=16\); option C is wrong because 0 does not satisfy the equation; option D is incomplete because it omits the negative root. Exam tip: when taking square roots always include both \(+\) and \(-\) solutions after squaring.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Quadratic Equations. Topic: Roots of a Quadratic Equation.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
