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To solve a problem with an absolute value function, it is important to know how the function works and be able to solve an equation out of context. Read up on the following concept sheet if necessary: Solving an Absolute Value Equation or Inequality.
The temperature throughout the day often follows the pattern of an absolute value function, which is the case for a typical beautiful sunny day in November! In the morning at 6 a.m., the temperature was -6 °C. As the sun rose higher in the sky, the temperature steadily increased until it reached a maximum of 9 °C by 4 p.m. From that point onwards, the temperature began to drop until midnight, following the same pattern as it did rising.
a) What was the temperature at noon and midnight?
b) At what hours was the temperature equal to the freezing point?
The previous example only dealt with equations, not inequalities. A final question that would have included inequalities could be: "During what time interval was the temperature above 5 °C?" To learn how to answer this kind of question, consult the following concept sheet: Solving an Inequality with an Absolute Value.