If the range of the function / [f (x) = / frac{ x }{ 4 }/] is {28, 30, 32, 34, 36}, what is its domain?

A) {112, 120, 128, 136, 144}

B) {118, 122, 124, 132, 145}

C) {110, 118, 122, 124, 137}

D) {111, 124, 128, 132, 146}

The answer is A. 112,120,128,136,144

Given the function f (x) = x4 f (x) = x4, substitute the range values into f (x) f (x) and solve for xx.

Substituting 28 into f (x) f (x):

28xx = x4 = 28⋅4 = 112 28 = x4 x = 28⋅4 x = 112

Substituting 30 into f (x) f (x):

30xx = x4 = 30⋅4 = 120 30 = x4 x = 30⋅4 x = 120

Substituting 32 into f (x) f (x):

32xx = x4 = 32⋅4 = 128 32 = x4 x = 32⋅4 x = 128

Substituting 34 into f (x) f (x):

34xx = x4 = 34⋅4 = 136 34 = x4 x = 34⋅4 x = 136

Substituting 36 into f (x) f (x):

36xx = x4 = 36⋅4 = 144 36 = x4 x = 36⋅4 x = 144

The domain of the given function then is { 112,120,128,136,144 }