Relation Function 7F1B76
1. **State the problem:** We have two relations $R_1$ and $R_2$ from set $A = B = \{1,2,3,4\}$ to itself.
2. **Define the relations:**
- $R_1 = \{(x,y) \mid x \in A, y \in B, x = y^2 + 1\}$
- $R_2 = \{(x,y) \mid x \in A, y \in B, x \text{ is even and } y \text{ is odd}\}$
3. **Recall the definition of a function:** A relation $R$ from $A$ to $B$ is a function if every element $x \in A$ is related to exactly one element $y \in B$.
4. **Analyze $R_1$:**
- For each $x \in A$, find $y$ such that $x = y^2 + 1$.
- Check $x=1$: $1 = y^2 + 1 \Rightarrow y^2 = 0 \Rightarrow y=0$ (not in $B$).
- $x=2$: $2 = y^2 + 1 \Rightarrow y^2=1 \Rightarrow y=\pm 1$; only $y=1$ in $B$.
- $x=3$: $3 = y^2 + 1 \Rightarrow y^2=2$ no integer $y$ in $B$.
- $x=4$: $4 = y^2 + 1 \Rightarrow y^2=3$ no integer $y$ in $B$.
- So $R_1 = \{(2,1)\}$ only.
- Since not every $x \in A$ has a corresponding $y$, $R_1$ is **not a function**.
5. **Analyze $R_2$:**
- $x$ must be even: $x \in \{2,4\}$.
- $y$ must be odd: $y \in \{1,3\}$.
- So $R_2 = \{(2,1), (2,3), (4,1), (4,3)\}$.
- For $x=2$, there are two $y$ values (1 and 3), so $x=2$ relates to multiple $y$.
- Hence, $R_2$ is **not a function** because $x=2$ has more than one image.
**Final conclusion:** Neither $R_1$ nor $R_2$ represents a function from $A$ to $B$.