SAT Math Question (6) - Functions

SAT Math tests generally have a lot of function related problems. These questions are usually very simple, just a plug in the x to get a y or vice versa, that some people have trouble with because they don't understand that. Here are a few questions that could be asked.

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Example 1 (Easy-Medium)

The temperature in Toronto is 56°F. Find the temperature in kelvins with the given function:

Solution:

First, C(F) just means your answer. It is just a function that gives the value of C given an F value. So, plug in F = 56 and simplify.

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Example 2 (Hard)

A company rents cars at $25 per day plus a $50 renters fee. The company made $675 on a rental. Make a function that models the profit (P), where x is number of days, and find how many days the car was rented.

Solution:

Well to make the function think of how muck they make after 1 day, 2 days, until you see a pattern. Notice there is an automatic $50 fee, so we add that on. Every day there is a $25 fee, so that is our multiplier. We can build the following equation:

Now, we plug in 675 into P(x) and solve.

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Not too bad, right Steemers? Hope you've enjoyed! Teach your kids!