The proof that the point [tex]\((1, \sqrt{3})\)[/tex] lies on the circle centered at the origin and containing the point [tex]\((0,2)\)[/tex] is found in the table below. What is the justification for the 4th statement?

\begin{tabular}{|c|c|}
\hline
Statement & Justification \\
\hline
\begin{tabular}{l}
A circle is centered at [tex]\((0,0)\)[/tex] and \\
contains the point [tex]\((0,2)\)[/tex].
\end{tabular} & Given \\
\hline
\begin{tabular}{l}
The radius of the circle is the distance \\
from [tex]\((0,0)\)[/tex] to [tex]\((0,2)\)[/tex].
\end{tabular} & Definition of radius \\
\hline
\begin{tabular}{l}
The distance from [tex]\((0,0)\)[/tex] to [tex]\((0,2)\)[/tex] is \\
[tex]\(\sqrt{(0-0)^2+(2-0)^2}=\sqrt{2^2}=2\)[/tex]
\end{tabular} & Distance formula \\
\hline
\begin{tabular}{l}
If [tex]\((1, \sqrt{3})\)[/tex] lies on the circle, it must be the same distance from the center as [tex]\((0,2)\)[/tex]. \\
The distance from [tex]\((0,0)\)[/tex] to [tex]\((1, \sqrt{3})\)[/tex] is \\
[tex]\(\sqrt{(0-1)^2+(0-\sqrt{3})^2}=\sqrt{1+3}=2\)[/tex]
\end{tabular} & Distance formula \\
\hline
\end{tabular}

Since [tex]\((1, \sqrt{3})\)[/tex] is 2 units from [tex]\((0,0)\)[/tex], it lies on a circle that is centered at the origin and contains the point [tex]\((0,2)\)[/tex].



Answer :

To provide a detailed, step-by-step solution for this proof, we need to establish that the point [tex]\((1, \sqrt{3})\)[/tex] lies on the circle centered at the origin and containing the point [tex]\((0,2)\)[/tex]. Here is the justification for each statement leading up to the conclusion:

1. Statement: A circle is centered at [tex]\((0,0)\)[/tex] and contains the point [tex]\((0,2)\)[/tex].
- Justification: Given.

2. Statement: The radius of the circle is the distance from [tex]\((0,0)\)[/tex] to [tex]\((0,2)\)[/tex].
- Justification: Definition of radius.

3. Statement: The distance from [tex]\((0,0)\)[/tex] to [tex]\((0,2)\)[/tex] is [tex]\(\sqrt{(0-0)^2 + (2-0)^2} = \sqrt{2^2} = 2\)[/tex].
- Justification: Distance formula.

Having established the radius of the circle, we move on to verify whether the point [tex]\((1, \sqrt{3})\)[/tex] lies on the same circle. We do this by calculating its distance to the center [tex]\((0,0)\)[/tex] and checking if it equals the radius of the circle.

4. Statement: If [tex]\((1, \sqrt{3})\)[/tex] lies on the circle, it must be the same distance from the center [tex]\((0,0)\)[/tex] as [tex]\((0,2)\)[/tex].
- Justification: Points on a circle are equidistant from the center by definition.

Next, we calculate the distance from [tex]\((0,0)\)[/tex] to [tex]\((1, \sqrt{3})\)[/tex].

5. Statement: The distance from [tex]\((0,0)\)[/tex] to [tex]\((1, \sqrt{3})\)[/tex] is [tex]\(\sqrt{(0-1)^2 + (0-\sqrt{3})^2} = \sqrt{1^2 + (\sqrt{3})^2} = \sqrt{1+3} = 2\)[/tex].
- Justification: Distance formula.

Finally, we draw our conclusion based on the computed distances.

6. Statement: Since [tex]\((1, \sqrt{3})\)[/tex] is 2 units from [tex]\((0,0)\)[/tex], it lies on a circle that is centered at the origin and contains the point [tex]\((0,2)\)[/tex].
- Justification: Definition of a circle.

Thus, we have shown step-by-step that the point [tex]\((1, \sqrt{3})\)[/tex] is indeed on the circle centered at [tex]\((0,0)\)[/tex] with radius 2.