## Precalculus: Mathematics for Calculus, 7th Edition

(a) First gap: square Second gap: add 3 (b) When $x=2$, $f(x)=7$ When $x=4$, $f(x)=3$ When $x=6$, $f(x)=7$
(a) Subtract 4, then square and add 3. (b) When $x=2$ $$f(2)=(2-4)^{2}+3=(-2)^{2}+3=4+3=7$$. When $x=4$ $$f(4)=(4-4)^{2}+3=0^{2}+3=3$$. When $x=6$ $$f(2)=(6-4)^{2}+3=2^{2}+3=4+3=7$$.