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Zorluk: KolayLinear Functions and Graphs

During a chemistry experiment, the temperature of a liquid sample is decreased at a constant rate. At the start of the experiment, the temperature of the liquid is 80C80^\circ\text{C}. After 44 minutes, the temperature of the liquid is 68C68^\circ\text{C}. If T(t)T(t) represents the temperature of the liquid, in degrees Celsius, tt minutes after the experiment starts, which of the following equations defines TT?

  1. T(t)=3t+80T(t) = -3t + 80Cevap
  2. B
    T(t)=3t+80T(t) = 3t + 80
  3. C
    T(t)=13t+80T(t) = -\frac{1}{3}t + 80
  4. D
    T(t)=80t3T(t) = 80t - 3

Cevap

The equation T(t)=3t+80T(t) = -3t + 80 correctly defines the temperature function.
The correct equation shows a starting value of 8080 and a rate of change of 3-3, which corresponds to the initial temperature of 80C80^\circ\text{C} and a decrease of 3C3^\circ\text{C} per minute.

Adım Adım Çözüm

1
Identify the yy-intercept (initial value) of the linear function.
The initial temperature at t=0t = 0 is 80C80^\circ\text{C}, so the yy-intercept bb is 8080.
The initial value of a linear relationship in context corresponds to the yy-intercept.
2
Calculate the slope (constant rate of change) using the coordinate points (0,80)(0, 80) and (4,68)(4, 68).
The slope mm is 688040=124=3\frac{68 - 80}{4 - 0} = \frac{-12}{4} = -3.
The slope is defined as the change in the dependent variable (temperature) divided by the change in the independent variable (time).
3
Substitute the slope mm and yy-intercept bb into the slope-intercept form T(t)=mt+bT(t) = mt + b.
T(t)=3t+80T(t) = -3t + 80
Substituting the specific slope and intercept values into the general form defines the particular function.

Anahtar Kavram

Determining a linear equation from a real-world scenario by identifying the initial value and constant rate of change.
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