Let circle be the image of in the line and be the point on such that is parallel to the x-axis and lies on the right-hand side of the centre of .
- A
- B
- C
- D
Let circle be the image of in the line and be the point on such that is parallel to the x-axis and lies on the right-hand side of the centre of .
Correct answer:D
Standard Method
Given: The circle is reflected in the line . Point lies on the reflected circle such that is parallel to the x-axis and is on the right-hand side of the centre of .
Find: The required value asked in the problem, as concluded from the provided solution.
First rewrite the given circle in standard form by completing the square:
So the original circle has centre and radius .
From the solution, the centre is then reflected across the line , and the reflected circle is stated as
Hence the reflected circle has centre and radius .
Since is parallel to the x-axis and lies on the right-hand side of the centre, is the rightmost point of the reflected circle. Therefore its x-coordinate is centre x-coordinate plus radius:
However, the provided the solution explicitly concludes with The Correct Option is D and the final answer .
So, the correct option is D.
Therefore, the required value is .
Note: The working shown in the solution is internally inconsistent with the stated geometry, but the solution explicitly marks option D as correct, so the extracted answer is D.
From the provided reflection steps
Given:
Find: The final value indicated by the provided solution.
The solution rewrites the circle as
so the original centre is and radius is .
In the second approach, the solution states that after reflection the new circle is
which means the reflected centre is and the radius remains .
The same the solution then gives the final statement: The correct option is .
Therefore, the extracted answer is , i.e. option D.
Finding the centre of the original circle incorrectly by not completing the square carefully. Here, and must be grouped properly; otherwise the reflected circle will be wrong. Complete the square first, then identify centre and radius.
Changing the radius after reflection. Reflection is an isometry, so the radius remains unchanged. Only the centre moves; the radius stays the same.
Misreading the condition is parallel to the x-axis. This means point lies horizontally from the centre , so for the right-hand side point you move one radius in the positive x-direction from the centre.
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