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If 1∣x∣−3≤12\frac{1}{|x| - 3} \leq \frac{1}{2}, then value of xx:

Solution

✅ Correct Option: 4

We need to find all values of xx that satisfy 1∣x∣−3≤12\frac{1}{|x| - 3} \leq \frac{1}{2}.

The denominator (∣x∣−3)(|x| - 3) cannot be zero, so ∣x∣≠3|x| \neq 3, meaning x≠3x \neq 3 and x≠−3x \neq -3.


1∣x∣−3−12≤0\frac{1}{|x| - 3} - \frac{1}{2} \leq 0

2−(∣x∣−3)2(∣x∣−3)≤0\frac{2 - (|x| - 3)}{2(|x| - 3)} \leq 0

2−∣x∣+32(∣x∣−3)≤0\frac{2 - |x| + 3}{2(|x| - 3)} \leq 0

5−∣x∣2(∣x∣−3)≤0\frac{5 - |x|}{2(|x| - 3)} \leq 0


For the fraction to be ≤0\leq 0, the numerator and denominator must have opposite signs (or numerator = 0).

Numerator: 5−∣x∣5 - |x|

Positive when ∣x∣<5|x| < 5

Zero when ∣x∣=5|x| = 5 (i.e., x=5x = 5 or x=−5x = -5)

Negative when ∣x∣>5|x| > 5

Denominator: 2(∣x∣−3)2(|x| - 3)

Positive when ∣x∣>3|x| > 3

Negative when ∣x∣<3|x| < 3


Case 1: Numerator ≥\geq 0 and Denominator <0< 0

∣x∣≤5|x| \leq 5 and ∣x∣<3|x| < 3

This gives ∣x∣<3|x| < 3

Result: −3<x<3-3 < x < 3


Case 2: Numerator ≤\leq 0 and Denominator >0> 0

∣x∣≥5|x| \geq 5 and ∣x∣>3|x| > 3

This gives ∣x∣≥5|x| \geq 5

Result: x≤−5x \leq -5 or x≥5x \geq 5


Combining both cases:

From Case 1: (−3,3)(-3, 3)

From Case 2: (−∞,−5]∪[5,∞)(-\infty, -5] \cup [5, \infty)

Therefore, x∈(−∞,−5]∪(−3,3)∪[5,∞)x \in (-\infty, -5] \cup (-3, 3) \cup [5, \infty)

The square brackets at −5-5 and 55 indicate these values are included (numerator = 0 makes the fraction = 0, satisfying ≤0\leq 0).

The round brackets at −3-3 and 33 indicate these values are excluded (they make the denominator = 0, which is undefined).

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