There are four situations.

1, when a/2 is less than or equal to 0.

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2. When a/2 is between 0 and 1.5.

The minimum value is x = a/2 and the maximum value is x = 3.

3. When a/2 is between 1.5 and 3.

The minimum value is x = a/2 (the same as the minimum value in case 2) and the maximum value is x = 0.

4. When a/2 is greater than 3.

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