Carmichael made a function machine. The inner workings of the machine are visible in the diagram below. What will the output be in each of the following cases?

1. If $3$ is dropped in?

   Step (a):

   Substitute $3$ for every $x$ (into $x^2+2x+1$).

   $(3)^2+2(3)+1$

   Answer (a):

   $16$

2. If $−4$ is dropped in?

   Hint (b):

   Substitute $(−4)$ for every $x$ in the expression.

3. If $−22.872$ is dropped in?

   Answer (c):

   $\approx478.38$