中等MATH-GEOM-009
What is the equation of the perpendicular bisector of the segment from (0, 0) to (4, 2)?
A. y = (1/2)x
B. y = −2x + 5✓ 答案
C. y = −2x + 1
D. y = 2x − 3
解說
The midpoint is (2, 1) and the segment slope is 1/2, so the bisector has slope −2 and equation y − 1 = −2(x − 2), that is y = −2x + 5. The line y = (1/2)x passes through the two endpoints.