Let be the set of all points in the x-y plane such that and . Then, the area, in square units, of the region represented by equals:
Let be the set of all points in the x-y plane such that and . Then, the area, in square units, of the region represented by equals:
Entered answer:
Solution
We need to find the area of region S defined by two conditions:
The condition represents all points inside and on a diamond shape (or square rotated 45°) centered at the origin.
When we consider all four cases:
If :
If :
If :
If :
The vertices of this diamond are at .
The condition means or .
This excludes the vertical strip where .
The region S is where both conditions are satisfied simultaneously.
Starting with our diamond , we remove the middle strip where .
This leaves us with four triangular regions:
Right Side ():
Upper right triangle: vertices
Lower right triangle: vertices
Left Side ():
Upper left triangle: vertices
Lower left triangle: vertices
Each triangle has:
Base = 1 (horizontal distance from to )
Height = 1 (vertical distance from to )
Area of each triangle =
Total area = square units
This approach is efficient because we visualized the geometric shapes instead of complex algebraic manipulation, identified the symmetry where all four triangles are congruent, and used the basic triangle area formula rather than integration.
Answer: 2
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