CPM Homework Help : CCA2 Problem 1-75

Function machine, with no input, or output, & rule is, x, squared, + 2, x, + 1. If the number $1$ is the output for Carmichael’s function machine shown at right, how can you find out what number was dropped in? Find the number(s) that could have been dropped in.

Hint:

Since $1$ is the output, set the expression inside of the function machine equal to $1$ .

Answer:

$x^2+2x+1=1$

$x^2+2x=0$

$x(x+2)=0$

Use the Zero Product Property: $x=0,x=−2$