The graph of the function f(x) is shown below. How many values of x satisfy f(f(x)) = 3?
The slope of the line = 3
The equation of the line is
f(x) = 3x - 5
f ( f(x)) = 3 (3x -5) - 5
So
3( 3x -5) - 5 = 3
9x -15 = 8
9x = 23
x = 23 / 9
Proof
f (23/9) = 3 (23/9) - 5 = 8/3
f ( 8/3) = 3 (8/3) - 5 = 3
