Expand your knowledge base with the help of IDNLearn.com's extensive answer archive. Our community provides timely and precise responses to help you understand and solve any issue you face.

In the linear function [tex]f[/tex], [tex]f(0) = 8[/tex] and [tex]f(1) = 12[/tex]. Which equation defines [tex]f[/tex]?

A. [tex]f(x) = 12x + 8[/tex]
B. [tex]f(x) = 4x[/tex]
C. [tex]f(x) = 4x + 12[/tex]
D. [tex]f(x) = 4x + 8[/tex]


Sagot :

To determine the equation of the linear function [tex]\( f(x) \)[/tex] that fits the given points [tex]\( f(0) = 8 \)[/tex] and [tex]\( f(1) = 12 \)[/tex], we can follow these steps:

1. Identify the form of the linear function: A linear function can generally be written in the form [tex]\( f(x) = mx + b \)[/tex], where [tex]\( m \)[/tex] is the slope and [tex]\( b \)[/tex] is the y-intercept.

2. Calculate the slope [tex]\( m \)[/tex]:
The slope [tex]\( m \)[/tex] between two points [tex]\((x_1, y_1)\)[/tex] and [tex]\((x_2, y_2)\)[/tex] is calculated as:
[tex]\[ m = \frac{f(x_2) - f(x_1)}{x_2 - x_1} \][/tex]
Using the points [tex]\((0, 8)\)[/tex] and [tex]\((1, 12)\)[/tex]:
[tex]\[ m = \frac{12 - 8}{1 - 0} = \frac{4}{1} = 4 \][/tex]

3. Determine the y-intercept [tex]\( b \)[/tex]:
The y-intercept [tex]\( b \)[/tex] is found by evaluating [tex]\( f(x) \)[/tex] when [tex]\( x = 0 \)[/tex]:
[tex]\[ f(0) = b \][/tex]
Given that [tex]\( f(0) = 8 \)[/tex], we have:
[tex]\[ b = 8 \][/tex]

4. Write the equation of the linear function:
Now, substituting the values of [tex]\( m \)[/tex] and [tex]\( b \)[/tex] into the general form [tex]\( f(x) = mx + b \)[/tex], we get:
[tex]\[ f(x) = 4x + 8 \][/tex]

Finally, comparing this equation with the given options:
- A) [tex]\( f(x) = 12x + 8 \)[/tex] (Incorrect, slope is 12 which doesn't match).
- B) [tex]\( f(x) = 4x \)[/tex] (Incorrect, missing y-intercept b).
- C) [tex]\( f(x) = 4x + 12 \)[/tex] (Incorrect, y-intercept is wrong).
- D) [tex]\( f(x) = 4x + 8 \)[/tex] (Correct, matches our equation).

Thus, the correct answer is:
[tex]\[ \boxed{D} \ f(x) = 4x + 8 \][/tex]