If $\frac{1}{|x|-3}≤\frac{1}{2}$, then value of $x$: |
$x ∈ (-∞,-6) ∪ (-3,3] ∪ (5,∞)$ $x ∈(-∞,5) ∪ (5,∞)$ $x ∈(-∞,-3) ∪ [3,∞)$ $x ∈(-∞,-5] ∪ (-3,3) ∪ [5,∞)$ |
$x ∈(-∞,-5] ∪ (-3,3) ∪ [5,∞)$ |
The correct answer is Option (4) → $x ∈(-∞,-5] ∪ (-3,3) ∪ [5,∞)$ ** Solve the inequality: $\displaystyle \frac{1}{|x|-3} \le \frac12$ 1. Domain $|x| - 3 \neq 0 \;\Rightarrow\; |x| \neq 3$ So $x \neq 3$ and $x \neq -3$. 2. Consider two cases based on the sign of the denominator Case 1: $|x| - 3 < 0$ → $|x| < 3$ Then the denominator is negative. $\displaystyle \frac{1}{\text{negative}}$ is always negative. RHS is positive ($\frac12$). A negative number is always $\le$ a positive number. So all $x$ with $|x| < 3$ satisfy the inequality: $(-3,\,3)$ Case 2: $|x| - 3 > 0$ → $|x| > 3$ Denominator positive → multiply without changing inequality: $\displaystyle \frac{1}{|x|-3} \le \frac12$ Multiply both sides by $(|x|-3)$: $1 \le \frac12(|x|-3)$ Multiply by 2: $2 \le |x|-3$ Add 3: $|x| \ge 5$ Thus: $x \le -5$ or $x \ge 5$ Final Answer ${(-\infty,-5] \;\cup\; (-3,3) \;\cup\; [5,\infty)}$ |