Analyzing the Setup
The real number line represents an infinite road stretching from −∞ to +∞. Our objective is to define two sets, A and B, and determine the result of the set difference B−A.
Decoding Set A
The Neighborhood
Set A is defined by the inequality ∣x∣<2. Geometrically, ∣x∣ represents the distance of a point x from the origin 0.
The condition ∣x∣<2 identifies all points whose distance from the origin is strictly less than 2. This creates a symmetric open interval centered at 0.
Decoding Set B
The Repulsion
Set B is defined by the inequality ∣x−2∣≥3. This implies that the distance of x from the point 2 must be at least 3.
This condition splits into two distinct linear inequalities:
1. x−2≥3⇒x≥5
2. x−2≤−3⇒x≤−1
Thus, the set
B consists of two rays:
B=(−∞,−1]∪[5,∞)
The Surgical Strike: B−A
The operation B−A requires us to take the set B and remove any elements that are also contained within set A. We must identify the overlap between B and A=(−2,2).
The ray (−∞,−1] overlaps with A in the interval (−2,−1]. Removing this overlap from the ray (−∞,−1] leaves us with the interval (−∞,−2].
The second part of B, which is [5,∞), shares no common elements with A. Therefore, this portion remains entirely unchanged.
Final Calculation
By combining the remaining segments, we arrive at the final set:
B−A=(−∞,−2]∪[5,∞)
This result represents all real numbers except those in the open interval
(−2,5). We can express this elegantly as:
R−(−2,5)
The final result is $(-\infty, -2] \cup