Question

Given the range of the function, find the corresponding domain. f(x) = 4x - 1 Range: {3, 7, 11, 15}

Answer 1

The range is the output value or the y value.
You would work backwards to find the domain.

f(x) = 4x - 1                              f(x) = 4x - 1
3 = 4x - 1                                    7 = 4x - 1
add 1 to both sides                    add 1 to both sides
4 = 4x                                            8 = 4x
divide both sides by 4              divide both sides by 4
x = 1                                              x = 2

f(x) = 4x - 1                                  f(x) = 4x - 1
11 = 4x - 1                                      15 = 4x - 1
add 1 to both sides                      add 1 to both sides
12 = 4x                                              16 = 4x
divide both sides by 4                  divide both sides by 4
x = 3                                                    x = 4
Domain { 1, 2, 3, 4}