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Home > PC > Chapter 3 > Lesson 3.1.2 > Problem 3-22


Julie has a fresh cup of hot coffee that has a temperature of . The temperature of the room is . Let number of minutes after Julie poured her coffee, and let the number of degrees the coffee is warmer than room temperature. In this situation for some constants and .

  1. Five minutes after Julie pours her coffee, its temperature is down to . Find and , and then write the particular equation for this situation.

    Remember that degrees above .
    1. Use the given information to write the coordinates of two points. Substitute them into the given situation for '' and ''.
    2. Then you will have two equations and two unknowns.
    3. Solve for the unknowns.

    Divide one of the equations by the other in other to solve!

  2. What does your model (equation) predict for the temperature of the coffee minutes later ( minutes after it was poured)?

    Did you remember to add to the answer using the above equation?