Respuesta :
Functions can be represented on graph and as equation.
- The domain and the range of the function are [0,3] and [54.4,133.6]
- The number of hours spent in 2000 is 107.2
- People spend about 120 hours per year in 2001
The function is given as:
[tex]f(x) = 26.4x + 54.4[/tex]
(a) The graph, domain and range
See attachment for the graph of [tex]f(x) = 26.4x + 54.4[/tex]
The function represents years from 1998 to 2001.
This means that:
[tex]x = 0[/tex] in 1998 and [tex]x =3[/tex] in 2001
So, the domain is: [tex][0, 3][/tex]
From the graph;
[tex]x = 0 \to f(x) = 54.4[/tex]
[tex]x = 3 \to f(x) = 133.6[/tex]
So, the range is [tex][54.4,133.6][/tex]
(b) Number of hours spent in 2000
First, we calculate x.
[tex]x = 2000 - 1998[/tex]
[tex]x =2[/tex] i.e. 2 years since 1998
So, we have:
[tex]f(x) = 26.4x + 54.4[/tex]
[tex]f(2) =26.4 \times 2 + 54.4[/tex]
[tex]f(2) =107.2[/tex]
(c) When people starts to spend 120 hours.
We have:
[tex]f(x) = 26.4x + 54.4[/tex]
Substitute 120 for f(x)
[tex]120 = 26.4x + 54.4[/tex]
Collect like terms
[tex]26.4x = 120 - 54.4[/tex]
[tex]26.4x = 65.6[/tex]
Solve for x
[tex]x = \frac{65.6}{26.4}[/tex]
[tex]x = 2.48[/tex]
Round 2.48 to the smallest integer greater than 2.48
[tex]x = 3[/tex]
This represents the number of years, since 1998.
So, the actual year is:
[tex]Year =1998 + 3[/tex]
[tex]Year = 2001[/tex]
Hence, people spend about 120 hours per year in 2001
Read more about functions and graphs at:
https://brainly.com/question/18806107
