Evaluate the integrals for $f(x)$ shown in the figure below. The two parts of the graph are semicircles.

a$){\displaystyle \underset{0}{\overset{2}{}}}3f(x)dx=$

$($i$)$

b$){\displaystyle \underset{0}{\overset{6}{}}}3f(x)dx=$

c$){\displaystyle \underset{1}{\overset{4}{}}}5f(x)dx=$

$($i$)$

d$){\displaystyle \underset{1}{\overset{6}{}}}|5f(x)|dx=$