Given that \(|x^2-2|>1\) and we need to find which of the following could not be a value of xLet's solve the problem using two methods
Method 1: SubstitutionWe will take each option choice and substitute it in \(|x^2-2|>1\) and see which one satisfies the equation
A. –1 => \(|(-1)^2 - 2| > 1\) => \(|1 - 2|>1\) => 1 > 1 =>
NOT POSSIBLEIn Test we don't need to check further, But I am solving to complete the solution.
B. –2 => \(|(-2)^2 - 2| > 1\) => \(|4 - 2|>1\) => 2 > 1 =>
POSSIBLEC. –3 => \(|(-3)^2 - 2| > 1\) => \(|9 - 2|>1\) => 7 > 1 =>
POSSIBLED. –4 => \(|(-4)^2 - 2| > 1\) => \(|16 - 2|>1\) => 14 > 1 =>
POSSIBLEE. –5 => \(|(-5)^2 - 2| > 1\) => \(|25 - 2|>1\) => 23 > 1 =>
POSSIBLESo,
Answer will be AMethod 2: Algebra\(|x^2 - 2| > 1\)
=> \(x^2 - 2\) > 1 or \(x^2 - 2\) < -1(Watch
this video to know about the
Basics of Absolute Value)
=> \(x^2\) > 1 + 2 or \(x^2\) < -1 + 2
=> \(x^2\) > 3 or \(x^2\) < 1
=> x > \(\sqrt{3}\) or x < -\(\sqrt{3}\) or -1 < x < 1
-2, -3, -4, -5 lie in x < -\(\sqrt{3}\) range
Only x = -1 is NOT in any of the above ranges
So,
Answer will be AHope it helps!
Watch the following video to learn How to Solve Absolute Value Problems