Question

Write a linear function f with the values f(−1)=8 and f(5)=6. A function is f(x)=

Answer 1

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Answer:

  f(x) = -1/3x +23/3

Step-by-step explanation:

You can use the linear regression function of a graphing calculator or spreadsheet to show you the equation of the line through these points:

  f(x) = -1/3x +23/3

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Approaching this in the usual way, we recognize we have points ...

  (-1, 8) and (5, 6)

The slope of the line through those points is ...

  m = (y2 -y1)/(x2 -x1)

  m = (6 -8)/(5 -(-1)) = -2/6 = -1/3

Then the point-slope equation of the line is ...

  y - 8 = -1/3(x +1)

Adding 8 gives us a form we can use for a function definition:

  f(x) = -1/3(x +1) +8

  f(x) = -1/3x +7 2/3