Let's calculate f(1)

f(x) = x³ - x
f(0) = 1³ - 1
f(0) = 0

So the point (1, f(1)) is the point (1,0)

Let's calculate f(2)

f(x) = x³ - x
f(2) = 2³ - 2
f(2) = 8 - 2
f(2) = 6

So the point (2, f(2)) is the point (2,6)

We plot those points:



Next we draw the graph (in red) and the secant line (in green):










That's the equation of the green secant line.

Edwin