- Relation \( a \) is a function: \( \text{True} \)
- Domain of relation \( a \): \( \{3, 4, 5, 19, -2\} \)
- Range of relation \( a \): \( \{-7, -6, 4, 5\} \)
- Relation \( b \) is a function: \( \text{False} \)
- Domain of relation \( b \): \( \{0, 4, -3, -2\} \)
- Range of relation \( b \): \( \{0, 4, 5, 8, 11\} \)
Thus, the final boxed answers are:
\[
\boxed{\text{Relation a is a function: True, Domain: } \{3, 4, 5, 19, -2\}, \text{ Range: } \{-7, -6, 4, 5\}}
\]
\[
\boxed{\text{Relation b is a function: False, Domain: } \{0, 4, -3, -2\}, \text{ Range: } \{0, 4, 5, 8, 11\}}
\]