Question

What is the range of the function, f(x)=3x+4, given the domain is {-2, 4,,10, 16}

Select one:
a. {-2, 19, 40, 58}
b. {-2, 0, 2, 4}
c. {-2, 4, 8, 13}
d. {-2, 16, 34, 52}

Answer 1

The range of f(x) is {-2 , 16 , 34 , 52} ⇒ answer d

Explanation:

* Lets talk about the domain and the range of a function

- The domain is the values of x (input)

- The range is the value of y of the corresponding x (output)

∵ f(x) = 3x + 4

∵ The domain is {-2 , 4 , 10 , 16}

- To find the corresponding range substitute the values of x in f(x)

∵ x = -2

- Substitute x by -2 in f(x)

∴ f(-2) = 3(-2) + 4 = -6 + 4 = -2

∵ x = 4

- Substitute x by 4 in f(x)

∴ f(4) = 3(4) + 4 = 12 + 4 = 16

∵ x = 10

- Substitute x by 10 in f(x)

∴ f(10) = 3(10) + 4 = 30 + 4 = 34

∵ x = 16

- Substitute x by 16 in f(x)

∴ f(16) = 3(16) + 4 = 52

∴ The range of f(x) is {-2 , 16 , 34 , 52}