JAMB Mathematics 2010 Paper

Concept:An inequality such as $x^2 > 1$ means the value of $x$ is more than one unit away from zero on the number line.Explanation:We need to solve $x^2 - 1 > 0$.Add $1$ to both sides to obtain $x^2 > 1$.Taking the square root of both sides gives $|x| > 1$.This is because $\sqrt{x^2} = |x|$.When $|x| > 1$, $x$ must be either greater than $1$ or less than $-1$.These two intervals are separate, so $x$ cannot lie between $-1$ and $1$.Thus, the solution set is $x \in (-\infty, -1) \cup (1, \infty)$.In simple form, $x < -1$ or $x > 1$.Answer:$x < -1$ or $x > 1$.Therefore, the correct option is A.