Question

Evaluate f(x) = x 2 + 1 for f(-1).

Answer 1

To evaluate this function for f(-1), plug -1 in for every x in the function.

f(x) = x² + 1 (given)

f(-1) = -1² + 1 (substitute)

f(-1) = 1 + 1 (square -1)

f(-1) = 2 (add)

Answer:

F(-1) = 2

Answer 2

Whenever you have a function, think of it like a machine. When you insert, let's say, meat into a meat grinder, the grinder "transforms" the meat as its function and outputs ground beef as a result. Here's it's really no different. Our meat is -1 and our meat grinder is
`f(x)=x^2+1`. Rather than making meat, though, our machine takes its input, squares it, then adds one. Now, let's insert -1 into our machine:

`f(-1)=(-1)^2+1=1+1=2`

Out function outputs 2 with an input of -1.