Look at the picture.
The point-slope form of a line:
[tex]y-y_1=m(x-x_1)\\\\m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]
We have the points (0, 1) and (2, 0). Substitute:
[tex]m=\dfrac{0-1}{2-0}=\dfrac{-1}{2}=-\dfrac{1}{2}\\\\y-1=-\dfrac{1}{2}(x-0)\\\\y-1=-\dfrac{1}{2}x\qquad|+1\\\\y=-\dfrac{1}{2}x+1[/tex]
Answer: [tex]f(x)=-\dfrac{1}{2}x+1[/tex]
