Analyzing Set A
The Rectangular Boundary
We are given the conditions ∣α−1∣≤4 and ∣β−5∣≤6. These absolute value inequalities represent distance constraints on the coordinate plane.
For the variable
α, the inequality
∣α−1∣≤4 expands to:
−4≤α−1≤4
Adding 1 to all parts, we find that
α is constrained to the interval:
−3≤α≤5
Similarly, for the variable
β, the condition
∣β−5∣≤6 expands to:
−6≤β−5≤6
Adding 5 to all parts, we find that
β is constrained to the interval:
−1≤β≤11
Geometrically, Set A defines a rectangle in the α-β plane where α∈[−3,5] and β∈[−1,11].
Analyzing Set B
The Elliptical Boundary
Set
B is defined by the inequality:
16(α−2)2+9(β−6)2≤144
To identify the shape, we divide the entire inequality by 144:
14416(α−2)2+1449(β−6)2≤1
This simplifies to the standard form of an ellipse:
9(α−2)2+16(β−6)2≤1
The ellipse is centered at (2,6) with semi-axes a=3 and b=4.
Determining the Subset Relationship
To determine if
B⊂A, we examine the extreme reach of the ellipse. The horizontal reach is determined by the center
α=2 plus or minus the semi-axis
a=3:
α∈[2−3,2+3]=[−1,5]
The vertical reach is determined by the center
β=6 plus or minus the semi-axis
b=4:
β∈[6−4,6+4]=[2,10]
We now compare these ranges to the boundaries of rectangle A:
1. The horizontal range [−1,5] is a subset of [−3,5].
2. The vertical range [2,10] is a subset of [−1,11].
Because the ellipse is a convex shape, if its bounding box fits entirely within the rectangle, the entire ellipse must also be contained within the rectangle.
Conclusion: B⊂A is true.