Đáp án:C
Giải thích các bước giải:
(C): $\left \{ {{I(2,1)} \atop {R=4}} \right.$
\(\begin{array}{l}
{T_{\overrightarrow v }}:(C) \to (C')\\
\leftrightarrow \left\{ \begin{array}{l}
R' = R = 4\\
I' = {T_{\overrightarrow v }}(I)
\end{array} \right.
\end{array}\)
\({T_{\overrightarrow v }}:I \to I' \leftrightarrow \overrightarrow {II'} = \overrightarrow v \leftrightarrow \left\{ \begin{array}{l}
x - 2 = 1\\
y - 1 = 3
\end{array} \right. \leftrightarrow \left\{ \begin{array}{l}
x = 3\\
y = 4
\end{array} \right. \leftrightarrow I'(3,4)\)
(C'): $\left \{ {{I'(3,4)} \atop {R'=4}} \right.$
-> pt (C')=(x-3)²+(y-4)²=16
