To analyze the function \( d = |0.5t - 6| \), we need to look at its behavior as \( t \) changes.
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Understanding the Absolute Value Function: The expression inside the absolute value, \( 0.5t - 6 \), will cross zero when \( 0.5t = 6 \) or \( t = 12 \). This is the point where the behavior of the function changes.
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Intervals:
- For \( t < 12 \): \( 0.5t - 6 < 0 \), thus \( d = -(0.5t - 6) = 6 - 0.5t \). In this interval, \( d \) will decrease as \( t \) increases.
- For \( t = 12 \): \( d = 0 \).
- For \( t > 12 \): \( 0.5t - 6 > 0 \), thus \( d = 0.5t - 6 \). In this interval, \( d \) will increase as \( t \) increases.
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Key Features:
- As the elevator approaches the 6th floor (from the ground floor), the distance \( d \) decreases at a constant rate until \( t = 12 \) seconds (6th floor).
- After reaching the 6th floor, as the elevator goes past it, the distance \( d \) increases at a constant rate.
Based on this analysis, the correct response is:
The function is a decreasing function and an increasing function, so as the person on the elevator travels from the ground floor to the 6th floor, the distance from the 6th floor decreases at a constant rate and as the person on the elevator travels away from the 6th floor, the distance from the 6th floor increases at a constant rate.