Find the domain and range of the function. (Enter your answers using interval notation.) f(x) = 3x, -9 = x = 7

Question

Find the domain and range of the function. (Enter your answers using interval notation.) f(x) = 3x, −9 ≤ x ≤ 7

Answer 1

Domain is the set of x values in which the function exists.  Range is the set of y values in which the function exists. 

 

It looks like your domain is all real numbers between -9 and 7 including -9 and 7.  So to find the range, we just evaluate f(x) at the end intervals.

 

f(x) = 3x

 

f(-9) = 3(-9) = -27

 

f(7) = 3(7) = 21

 

 

Domain = [-9, 7]

Range = [-27, 21]