Question

When a window is open, the temperature in a room falls 5ºF every 15 minutes. Before the window is opened, the temperature was ​ 70ºF​ .

Use the Ray tool to make a graph that shows the temperature of the room, T, after the window has been open for m minutes.

Keyboard Instructions
Initial graph state
The horizontal axis goes from -4.5 to 47.5 with ticks spaced every 5 unit(s).
The vertical axis goes from -4.5 to 84.5 with ticks spaced every 5 unit(s).
Temperature vs. Time Window Is Open
Time (min)Temperature (°F)

Answer 1

Equation: T(m) = 70 − (1/3)m for m ≥ 0.

Reason: temperature falls 5°F every 15 min → slope = −5/15 = −1/3 °F per minute. At m = 0, T = 70.

Points to plot: (0, 70), (15, 65), (30, 60), (45, 55).

Ray tool instructions: place the ray's endpoint at (0, 70) and draw it through (45, 55) (direction vector (1, −1/3)), extending to the right. Label the horizontal axis Time (min) and the vertical axis Temperature (°F).