1. The relation is a function.

3. −16

5. The graph is a parabola and the graph fails the horizontal line test.

7. $2{a}^{2}-a$

9. $-2\left(a+b\right)+1$

11. $\sqrt{2}$

13.

15. even

17. odd

19. x = –7 and x = 10

21. ${f}^{-1}\left(x\right)=\frac{x+5}{3}$

23. $\left(-\infty ,-1.1\right)\text{ and }\left(1.1,\infty \right)$

25. $\left(1.1,-0.9\right)$

27. $f\left(2\right)=2$

29. $f\left(x\right)=\begin{cases}|x|\text{ if }x\le 2\\ 3\text{ if }x>2\end{cases}$

31. $x=2$

33. yes

35. ${f}^{-1}\left(x\right)=-\frac{x - 11}{2}$