Given:
The function is:
[tex]f(x)=-2x+1[/tex]
To find:
a. Slope and Y-intercept.
b. Is the function increasing, decreasing, or constant, justify your answer.
c. Graph the function, label x, and y-intercepts.
Solution:
a. We have,
[tex]f(x)=-2x+1[/tex] ...(i)
The slope intercept form of a line is:
[tex]y=mx+b[/tex] ...(ii)
Where, m is the slope and b is the y-intercept.
On comparing (i) and (ii), we get
[tex]m=-2,b=1[/tex]
Therefore, the slope of the line is -2 and the y-intercept is 1.
b. If the slope of a linear function is negative, then the function is decreasing.
If the slope of a linear function is positive, then the function is increasing.
If the slope of a linear function is 0, then the function is constant.
The slope of the linear function is negative.
Therefore, the function is decreasing.
c. We have,
[tex]f(x)=-2x+1[/tex]
At [tex]x=0[/tex], we get
[tex]f(0)=-2(0)+1[/tex]
[tex]f(0)=1[/tex]
So, the y-intercept is at (0,1).
At [tex]f(x)=0[/tex], we get
[tex]0=-2x+1[/tex]
[tex]2x=1[/tex]
[tex]x=\dfrac{1}{2}[/tex]
[tex]x=0.5[/tex]
So, the x-intercept is at [tex]\left(0.5,0\right)[/tex].
Plot the points [tex](0,1), \left(0.5,0\right)[/tex] and connect them by a straight line as shown below:
