Example 1

Topic:
Logarithm
The number of electric vehicles () sold in the United States within 3 years of their introduction to the market can be modeled by the logarithmic function , where is the number of vehicles sold in thousands and is the number of years after introduction to the market. The number of hybrid vehicles () sold within 3 years of their introduction to the market can be modeled by the logarithmic function . At what value of was an equal number of each vehicle sold, and which type of vehicle had greater sales over the 3 introductory years? Explain your reasoning with references to the terms in the function and how they compare.
  1. Set .
  2. Solve the resulting equation for .
  3. Rewrite the resulting equation using an inverse function.
  4. Interpret the resulting value of in terms of the conditions of the original problem.
  5. Check the value of found in step 3 by substituting it back into the functions and .
  6. Show which vehicle type had greater sales over the 3-year period by comparing the characteristics of each function.
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