Precalculus (6th Edition)

(a) $f(2)=5$ (b) $f(-1)=11$
(a) The value of $f(2)$ is the second coordinate of the ordered pair whose first coordinate is $2$. The function contains the point $(2, 5)$. Thus, $f(2) = 5$. (b) The value of $f(-1)$ is the second coordinate of the ordered pair whose first coordinate is $-1$. The function contains the point $(-1, 11)$. Thus, $f(-1) = 11$.