Question Analysis
This question is about using the midpoint formula in reverse in coordinate geometry.
Key Concept Explanation
The midpoint formula for two points and is . When we know the midpoint and one endpoint , we can re - arrange the formula to find the other endpoint .
Step - by - Step Solution
1. Let the coordinates of point be .
Given the midpoint and point .
For the -coordinate:
Using the midpoint formula , where , , and .
Substitute into the formula: .
Multiply both sides by 2: