## Precalculus: Mathematics for Calculus, 7th Edition

$f(x+2) =x^2 + 4x + 5$; $f(x) + f(2) = x^2 + 6$
For x = x+2 $f(x+2) = (x+2)^2 + 1$ ... square (x+2) $= x^2 +4x +4 +1$ ... add $= x^2 +4x +5$ _____________ For x = 2 $f(2) = (2)^2+1$ ... square 2 $= 4 + 1$ ... add $=5$ therefore $f(x) + f(2) = x^2 + 1 + 5$ ... add $= x^2 + 6$