To analyze the function \( d = |0.5t - 6| \), let's break it down.
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Intercepts and Key Points: The expression inside the absolute value is zero when \( 0.5t - 6 = 0 \), or \( t = 12 \). This is the point in time when the elevator reaches the 6th floor (this calculates the distance from the 6th floor to be zero).
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Behavior of the Function:
- For \( t < 12 \): \( 0.5t - 6 < 0 \), thus \( d = 6 - 0.5t \) (the distance decreases as \( t \) approaches 12).
- For \( t > 12 \): \( 0.5t - 6 > 0 \), thus \( d = 0.5t - 6 \) (the distance increases as \( t \) moves away from 12).
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Increasing and Decreasing:
- For \( t < 12 \), the function is decreasing.
- For \( t > 12 \), the function is increasing.
Based on these observations, the correct interpretation is that both increasing and decreasing behaviors are present:
- As the person on the elevator travels from the ground floor to the 6th floor (i.e., as \( t \) increases from 0 to 12), the distance from the 6th floor decreases at a constant rate (linear decrease).
- After reaching the 6th floor (when \( t > 12 \)), the distance from the 6th floor increases at a constant rate.
Thus, the most accurate 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 6th floor increases at a constant rate.