Defined on the set of real numbers R,
$$\begin{aligned} & \beta _ { 1 } = \left\{ ( x , y ) : x ^ { 2 } + y ^ { 2 } = 1 \right\} \\ & \beta _ { 2 } = \left\{ ( x , y ) : x ^ { 2 } + y = 2 \right\} \\ & \beta _ { 3 } = \left\{ ( x , y ) : x - y ^ { 2 } = 3 \right\} \end{aligned}$$
Which of these relations define a function of the form $\mathbf { y } = \mathbf { f } ( \mathbf { x } )$ on $R$?
A) Only $\beta _ { 1 }$
B) Only $\beta _ { 2 }$
C) $\beta _ { 1 }$ and $\beta _ { 3 }$
D) $\beta _ { 2 }$ and $\beta _ { 3 }$
E) $\beta _ { 1 } , \beta _ { 2 }$ and $\beta _ { 3 }$
Defined on the set of real numbers R,

$$\begin{aligned}
& \beta _ { 1 } = \left\{ ( x , y ) : x ^ { 2 } + y ^ { 2 } = 1 \right\} \\
& \beta _ { 2 } = \left\{ ( x , y ) : x ^ { 2 } + y = 2 \right\} \\
& \beta _ { 3 } = \left\{ ( x , y ) : x - y ^ { 2 } = 3 \right\}
\end{aligned}$$

Which of these relations define a function of the form $\mathbf { y } = \mathbf { f } ( \mathbf { x } )$ on $R$?\\
A) Only $\beta _ { 1 }$\\
B) Only $\beta _ { 2 }$\\
C) $\beta _ { 1 }$ and $\beta _ { 3 }$\\
D) $\beta _ { 2 }$ and $\beta _ { 3 }$\\
E) $\beta _ { 1 } , \beta _ { 2 }$ and $\beta _ { 3 }$