Answer:
f(4) = 3
x = -1
Step-by-step explanation:
Line graphed shows a linear function.
Since this line passes through two points (4, 3) and (-1, 4)
Let the function is,
f(x) = mx + b
where 'm' = slope of the line
b = y-intercept of the line
Slope 'm' = [tex]\frac{y_2-y_1}{x_2-x_1}[/tex]
= [tex]\frac{4-3}{-1-4}[/tex]
= [tex]-\frac{1}{5}[/tex]
f(x) = [tex]-\frac{1}{5}x+b[/tex]
Since a point (4, 3) lies on the line,
f(4) = [tex]-\frac{1}{5}(4)+b[/tex]
3 = [tex]-\frac{4}{5}+b[/tex]
b = 3 + 0.8
b = 3.8
Therefore, f(x) = -0.2x + 3.8
For x = 4
f(4) = -0.2(4) + 3.8
= -0.8 + 3.8
= 3.0
For f(x) = 4
4 = -0.2x + 3.8
0.2x = 3.8 - 4
x = [tex]\frac{-0.2}{0.2}[/tex]
x = -1
