Answer with explanation:
The given function is :
f(x)= -x
Replacing , f(x) by , y in the above equation ,the equation of the function changes to,
→ y= -x
→x+y=0
To Plot the Line in x y Plane, take any one of the variable among x and y as Independent Variable and any other as Dependent variable and calculate two real values of each that is x and y.
x=0, gives , y=0
And, x=1 , gives , y= -1.
To get a unique line you need two points, those two points are, (0,0) and (1, -1).
Mark these points in x y plane and produce the two ends infinitely in both direction.